McLouth, the Pirates' All-Star representative and a Gold Glove winner in 2008, is starting in left field. The 30-year-old was batting .244/.325/.461 with 10 homers and 33 RBIs in 47 games with the Tides.
Chavez batted .190 in 47 games with the Orioles.
McLouth, who's wearing No. 48, found out yesterday that the Orioles were selecting his contract, though reporters here were told that the club wouldn't know whether he was opting out until today.
"I was just at a point to where I felt that opting out was the best way to go and I was comfortable with whatever decision was made. I'm certainly happy that I'm up here, though," he said.
"It can be a tense time, but I have faith in God's plan for my life and I was good either way. Like I said, I'm certainly happy that it turned out the way it did, but I was comfortable either way."
McLouth, 30, arrived in Tampa late last night. He didn't play in Norfolk's last two games.
"I started off kind of rough in the sense that I just wasn't getting any hits," said McLouth, who batted .292 with eight homers and 24 RBIs in his last 27 games, but .211 with no homers and two RBIs in his last 10.
"I've felt comfortable with my approach, especially in the last month. I got to the point that I detached my feelings from the result of the at-bat and just really focused on the process of the at-bat, and I think that's the best way to go. I'm comfortable with where I'm at."
McLouth is starting tonight in his first career game at Tropicana Field, but he isn't sure how often his name will appear in the lineup.
"It's a great opportunity," said McLouth, a career .246 hitter with 142 doubles, 14 triples, 81 homers and 272 RBIs in 765 major league games with the Pirates and Braves. "I don't know what my role's going to be and frankly, I'm looking forward to it, whatever it's going to be. I'm thankful for the opportunity and excited to get started.
"With Pittsburgh this year, I didn't get a lot of consistent at-bats. I knew that was the role I was going to have - pinch hitting and starting here and there. I wasn't able to gain a comfort level in that particular role, but being in Triple-A and playing every day and getting those consistent at-bats, it's a big difference and really gives you respect for those guys who can excel in those bench roles and come in and face eighth- and ninth-inning guys and have success, because it's a really tough thing to do. But yes, I'm looking forward to getting started here."
For the Orioles:
Nick Markakis RF
J.J. Hardy SS
Chris Davis DH
Adam Jones CF
Matt Wieters C
Wilson Betemit 3B
Nate McLouth LF
Mark Reynolds 1B
Omar Quintanilla 2B
Wei-Yin Chen LHP
For the Rays:
Down on the farm, Norfolk first baseman Joe Mahoney is batting .340 (17-for-50) with six doubles, three homers and eight RBIs in his last 13 games. Mahoney hit .322 (29-for-90) with 12 doubles, three homers and 11 RBIs in July, the fourth consecutive month that he upped his batting average (.232 in April, .243 in May, .271 in June).
With just two errors in 934 total chances, Mahoney leads International League first basemen with a .998 fielding percentage.
Corner infielder Brandon Waring is one home run shy of reaching the 20-homer plateau for the sixth consecutive season. He hit 11 with Double-A Bowie before moving up to Norfolk.
How's this for consistency? The Tides have won 10 series, lost 10 series and split 10 series.