The 23-year-old linebacker announced his retirement from the NFL this afternoon, Ravens general manager Ozzie Newsome said.

"Rolando let me know that he plans to retire from the NFL," Newsome said in a statement. "We have placed him on the reserve/retired list."

Baltimore had signed McClain to a one-year contract on April 12, hoping he could come closer to fulfilling his massive potential at middle linebacker. The Raiders selected him eighth overall in 2010 and he spent his first three professional seasons with Oakland before being cut loose this offseason.

He signed with the Ravens and was arrested for the third time since 2011 on April 21, this time for disorderly conduct and resisting arrest.

McClain recorded 274 tackles (195 solo), 6.5 sacks (for minus-42.5 yards), one interception, one forced fumble and 23 passes defensed in 41 career games with the Raiders.

Spagnuolo will serve as a senior defensive assistant under coordinator Dean Pees. He has spent 14 years as an NFL coach, with his last three jobs being Saints defensive coordinator (2012), Rams head coach (2009-11) and Giants defensive coordinator (2007-08).

He has extensive familiarity with Ravens coach John Harbaugh from their seven seasons together on the Eagles staff.

Spagnuolo has been a part of eight playoff teams, six division title winners, five conference championship game appearances and the Giants' Super Bowl XLII victory.

"Steve had a number of opportunities in the league right now, and we're excited he picked the Ravens," Harbaugh said in a statement. "He comes to a staff that we believe is very strong, and he makes us even better. His wealth of NFL coaching experience speaks for itself, and he'll help us across the board. We think he can help with every position on the defense, and we'll take full advantage of his knowledge and excellent teaching abilities. The Ravens got better today with the addition of an outstanding coach and person like Steve."

This isn't the first addition to the 2013 staff from Harbaugh's Eagles days. Baltimore hired longtime Philadelphia assistant Juan Castillo to be its running game coordinator.

Baltimore agreed in principle to a new two-year contract with left tackle Bryant McKinnie, according to the team's website.

McKinnie, 33, returns to the Ravens for a third straight season after a strange year where he came to training camp late, struggled to get in shape and didn't start a single game during the regular season. But the former Pro Bowler reclaimed his starting job for the team's run to the Super Bowl, and was a key part of an offensive line that performed superbly during the postseason.

McKinnie reportedly visited the Miami Dolphins and San Diego Chargers before opting to return to Baltimore.

That provides the unit with some continuity after center Matt Birk's retirement, leaving the offensive line with just one big hole to fill.

Update: The Ravens also have agreed to terms on a four-year deal with sixth-round defensive end Kapron Lewis-Moore, according to The Sun.

Lewis-Moore is the first Ravens draft pick to come to terms.

Baltimore acquired the 56th overall pick from Seattle for their second-round pick (No. 62), as well as a fifth-rounder (No. 165) and a sixth-rounder (No. 199) this year.

Hall of Fame elect Jonathan Ogden made the selection of Brown, who should help make up for the losses of Ray Lewis, Dannell Ellerbe and Paul Kruger.

ESPN.com's Mel Kiper projected Brown being selected at No. 45 by the San Diego Chargers, who instead picked Manti Te'o.

Of Brown, Kiper wrote, "Versatile LB with great athleticism. Fills an immediate need."

Brown led Kansas State with 100 tackles, including seven for loss and a sack, in 2012. He added two interceptions.

Update: In the third round, the Ravens kept addressing their defense by taking Missouri Southern State's Brandon Williams, a 6-foot-3, 325-pound defensive tackle.

Williams was named D2football.com National Defensive Player of the Year. He was the school's all-time leader with 27 career sacks. He finished second on the team with 68 tackles, including 16.5 for loss and 8.5 sacks, and five forced fumbles in 2012.

The former Gators safety made quite an impression on Muschamp, who sees Elam having a bright future.

"I think he'll be very successful," Muschamp said. "Matt is extremely intelligent. He can play multiple positions. He can do a lot of things for you. He is a physical, tough football player. He plays the game the way it's supposed to be played. He is a guy that throws his body around. He is a reckless football player. He has ball-hawk ability as far as creating turnovers and being a part of gaining the ball back for the Ravens. So I think he's going to be outstanding.

"He is a really good communicator. He can handle everything that you ever want to do defensively. He communicates well. He sees the game very well. He's just a really good football player. I think this past year, he was as productive of a defensive football players as I've been around."

Muschamp described Elam as a great competitor, someone who really loves football and, because of that, a natural leader. On top of that, Elam sure can tackle.

"He is a violent tackler. He has really good explosion in a short area," Muschamp said. "He can really snap his hips in a short area, so a guy that is a good box safety. He can do that. He can still also play with range in the middle of the field and tackling and running in the alleys and different things. He's a physical football player."

Muschamp believes Elam has to go through the normal progression of adjusting to the NFL like every other young player.

"The different hash marks, the different markings on the field," Muschamp said. "Obviously, going against the type of caliber athletes and adjusting to the speed of the game - the natural progression that any rookie goes through and adjusting to the NFL. It's a long season. When you hit Thanksgiving, you have five, six games left, and that's not including the playoffs there for the Ravens.

"The natural things that happen for any rookie, those are the things he has to be able to adjust to. But again, I go back to he's a very mature young man, and he's very intelligent. Generally, those guys that have those two qualities adjust well."

Elam is a little undersized at 5-foot-10, but Muschamp doesn't believe that will limit him.

"I think again that can be a little overrated at times. What's the difference between 5-10 and 6-foot?" Muschamp said. "He has great leaping ability, and he has really good ball judgment. As far as playing the ball and getting the ball off of people and being strong-handed in coverage, (those) are things that, I think, are some of his strengths. I think that overcomes those two inches that people may point at."

Yet, it was Baltimore that saved him from falling to the second round, taking him at No. 32 Thursday, and Elam said he now has something to show the rest of the teams that let him slide.

"I just want to go out and prove to them, and make them realize why I feel like I was the best college safety coming out," he said via conference call. "So I've got a big chip on my shoulder. I'm going to work and I'm going to show it."

So what exactly does the Florida product think he can bring to the Ravens?

"I feel like I'm going to bring a lot of competitiveness, a lot of energy to a great defense already," Elam said. "I just feel excited to have the opportunity, just coming in, a great player like Ed Reed, who was back there before, that's a lot of big shoes to fill. I'm coming in to do all I can to get wins and hopefully win a championship."

Elam has had some exposure to the NFL through his older brother, Abram, who has played safety for the Dallas Cowboys, New York Jets, Cleveland Browns and Kansas City Chiefs over eight seasons in the league.

"I feel like it gives me an advantage because my brother has a lot of experience," Elam said. "He's played in the league and he knows what it takes. He's been giving me a lot of advice, like covering and the way to train and the way to take care of my body. It's just being a pro. That's what he taught me the most."

Perhaps the reason some teams didn't view Elam as the best college safety was because of his height. At 5-foot-10, he's a little undersized for the position.

But that didn't deter the Ravens and isn't a concern to Elam.

"I just feel like my size doesn't matter because I'm a great competitor, I'm flying around, I'm hitting guys, I'm hitting guys bigger than me," he said. "So I feel like size doesn't matter."

Baltimore had linebacker Manti Te'o and wideout Robert Woods available to them at No. 32, but opted to go with a safety.

Update: The 5-foot-10 Elam comes to the Ravens after spending three years with the Gators. He played in 39 games at Florida, starting his last 26 at strong safety. Noted as a big hitter, he finished his career with 176 tackles (124 solo), five sacks and 24 tackles for loss. He made six interceptions and forced two fumbles.

Elam, 21, has the NFL in his blood, as his older brother Abram is entering his eighth season in the league.

Assistant general manager Eric DeCosta, director of college scouting Joe Hortiz and coach John Harbaugh exchanged smiles and handshakes as they left the press conference to discuss their newest addition. It was clear they got the guy they wanted.

"Even though it was a position of need, whether you all believe it or not, he was the highest-rated player on our board," general manager Ozzie Newsome said. "The thing that I think we all like about Matt is his speed. He's probably one of the better tacklers that we've seen play the position and the other thing that we looked at too, he enjoys practicing. He enjoys playing the game of football.

"He will come in. I still don't know if he'll get into the starting lineup (right away). That'll be up to John. But he's a guy with the type of speed and the way he plays the game, he'll be a presence on special teams right away.

"Matt Elam is our guy. I think if you would ask any of the four of us what one player we would like to have had today, I think each one of us would have written down on a sheet of paper, we would've said Matt Elam."

Harbaugh echoed those sentiments, saying his wife asked who he'd like to see the Ravens draft in the first round. His response: Matt Elam.

Elam has connections with the Ravens through defensive backs coach Teryl Austin, who served as his defensive coordinator at Florida for one season, and special teams coordinator Jerry Rosburg, who has a longtime connection to Elam's brother.

"I'm just very excited. He's the player that we saw quite a bit of tape on and had a good connection to the Florida coaching staff," DeCosta said. "He's just an infectious kid on the playing field - talk, aggressive, good cover skills, can play in the slot, he's a great special teams guy."

Said Hortiz: "He's a versatile kid, as tough as they come and will add a lot. He fits our profile for a player and plays like a Raven, so we're excited."

The Ravens also had a positional need at inside linebacker. And while many pundits projected Te'o to go before Baltimore picked in the first round, the Ravens let him slide into the second round.

Newsome said the reason the team went with Elam was simple.

"Matt was the higher-rated player between the two of those guys," Newsome said.

The Ravens were unconcerned with Elam's height, and Harbaugh said he'll have an opportunity to start immediately.

"He definitely has a chance to do that. He'll have to earn it," Harbaugh said. "We've got one veteran safety in there and some of our young guys will be competing for it as well. We always play the best guy and we'll have to see who's playing the best. But I think Matt Elam will be right in the middle of that fight and we expect him to be."

As the likes of Ray Lewis and Ed Reed have departed, a new era of football in Baltimore is on the way. And while the faces will be Joe Flacco, Ray Rice, Terrell Suggs and Elvis Dumervil, the foundation of its future will begin to be laid down tonight when the NFL draft gets under way at 8 p.m.

Ravens fans will be waiting far longer than that, as the team's first pick doesn't come until No. 32, the last selection of the opening round.

But with 12 picks over the next three days, the Ravens know this draft will be a crucial one.

"I would say it's important. It's very important," coach John Harbaugh said. "With the transition and some of the guys that we're talking about that aren't here and the transition of our football team, it's going to be very important. It's going to be important to get the right guys. We're working hard at it, and I am really excited about it.

"I think our scouts have done a tremendous job. We were in those meetings for the last week, and you see the work they've done and the reports they read, and the consensus that we came to on a lot of different players after we hashed it all out, they were very prepared. They've just done a great job across the board, and that's what really makes the draft - that's where it all starts, like (general manager Ozzie Newsome) was talking about. So to me, we've got a good foundation, a good basis for having a great draft because of the work they've done."

This might not be the best year for such an important draft to the Ravens. One high-ranking NFL executive told CBS Sportsline this year's class could be a forgettable one.

"When we look back at this draft in five or 10 years," said the team executive, "we might view it as one of the worst we've seen in some time."

But Ravens assistant general manager Eric DeCosta believes the strength of this draft is depth.

"I think numbers-wise, we see an extra round, basically, and about 32 or 35 extra players that we think are draftable players in this draft," DeCosta said. "So the pool of players is greater. I think the quality of player between 15 and 45 is excellent. I think there are players in every round that we like, slotted very well.

"Defensively, it's a very, very strong draft. Offensively, pretty good, too. Up front on the defensive and offensive lines, we see a lot of really good players. With the amount of juniors that came out this year, that really bolstered the crop of players. I think 74 juniors came out this year, and that really increased the depth as well."

So what exactly do the Ravens need?

With the retirement of Lewis and departure of Dannell Ellerbe, inside linebacker is a position of need, and maybe more so because of the uncertain future of the recently signed Rolando McClain.

Baltimore could also use help at safety even though Michael Huff was signed to replace Reed. Offensive tackle and wide receiver are the Ravens' biggest holes on offense with wideout Anquan Boldin gone and tackle Bryant McKinnie still a free agent. Both could be addressed in this draft as well.

The Ravens have undergone the most turnover on defense, and have added plenty there with Dumervil, Chris Canty and Marcus Spears in the front seven and Huff at safety. Newsome said the offseason acquisitions won't affect Baltimore's approach, but he did acknowledge it could be a defense-heavy draft.

"To say we aren't going to take the best player, that would be wrong," Newsome said. "But like at the outset, they talked about us taking some interior defensive linemen. We could do that. Could we take some inside linebackers? We could do that. Could we take some safeties? We could do that. We won't pass up a good corner. You don't ever have enough good corners. You don't ever have enough good pass rushers.

"So could we come away and say out of the 12 picks - if we use all of them - seven or eight could probably be on defense? Yes. But they will be the best players at the time we pick them."

Newsome said the team likes this year's safety class and sees at least one in all seven rounds that it could take.

The pundits are all over the board with their predictions for who the Ravens will take in the first round.

Each of CBS Sportsline's four analysts had a different pick at No. 32 of their mock drafts - USC wideout Robert Woods, LSU inside linebacker Kevin Minter, Florida State offensive tackle Manelik Watson and Syracuse offensive tackle Justin Pugh.

At ESPN, Mel Kiper's latest mock draft has the Ravens taking Minter and Todd McShay has them selecting Florida safety Matt Elam.

So, two have Minter going to the Ravens, two have them taking offensive tackles, one has a wide receiver and one a safety. And don't forget the longtime buzz that they could end up with Notre Dame linebacker Manti Te'o, or the possibility of them trading up or out of the first round.

We shall see in a matter of hours.

This time, the 23-year-old was charged with disorderly conduct and resisting arrest, according to AL.com. McClain was released on $1,000 bond.

This marks his third arrest since 2011, and further brings his character into question after he was suspended by the Raiders for the final two games last season for conduct detrimental to the team.

Whether McClain lasts with the Ravens remains to be seen, but his latest off-field incident can't help his case one bit. Baltimore signed the former top-10 pick to a low-risk one-year contract and general manager Ozzie Newsome implied that McClain would have to earn a spot on the 53-man roster.