CLEVELAND - Gunnar Henderson is starting at shortstop tonight as the Orioles conclude their road trip and try to win their series against the Guardians.

He stays on the left side of the infield.

Henderson is batting fifth behind Ramón Urías, who moves to third base.

Jorge Mateo and Austin Hays are on the bench. Jesús Aguilar is the designated hitter in his first game with the Orioles.

Terrin Vavra is in left field and batting ninth, and Anthony Santander is in right.

CLEVELAND – The Orioles designated infielder Richie Martin for assignment this afternoon to make room on the 40-man roster for first baseman Jesús Aguilar, whose contract was selected after he signed a minor league deal yesterday and joined the taxi squad.

Left-hander DL Hall was recalled today to give the Orioles 28 players in the new month, which begins with them only two games out of third place and two behind the last wild card spot.

Aguilar is the first Oriole to wear No. 99.

Martin, 27, was selected from the Athletics in the 2018 Rule 5 draft. He appeared in 120 games in 2019 as the primary shortstop, but only 50 between 2021-22 due to injuries and his struggles at the plate, where he hit .212/.261/.311.

At Triple-A Norfolk, Martin was batting .244/.338/.360 with 17 doubles, four triples, one home run, 21 RBIs and 20 stolen base in 24 attempts.

A nine-inning baseball game last night felt like the calmest moment that the Orioles experienced, even in the heat of a pennant race.

Roster moves were distributed to the media as if shot out of a T-shirt gun. The spring training schedule was released, minus report dates and times.

The pace figures to slow today, with just the corresponding 40-man roster move to accommodate first baseman Jesús Aguilar.

Active rosters grow from 26 to 28 players, and we already know that the Orioles are using those spots on Aguilar and left-hander DL Hall.

Rewinding to yesterday’s activity, the biggest surprise might have been the selection of Gunnar Henderson’s contract rather than his placement on the taxi squad, which was the plan Tuesday night.

CLEVELAND – The Hall of Fame pitcher leaned over the dugout railing this afternoon to shake hands with the 21-year-old infielder preparing to make his major league debut.

A link to the Orioles’ glorious past meeting baseball’s No. 1 prospect and a huge cog in the rebuild that is designed to move them back into contention.

Jim Palmer headed up to the MASN broadcast booth. Gunnar Henderson took batting practice, started at third base and dived into the next phase of his professional life.

Of course, he landed on his feet, and used them to circle the bases on his first major league hit.

Henderson launched a 429-foot home run to right-center field off Tristen McKenzie leading off the top of the fourth inning, deepening a lead that evolved into a 4-0 victory over the Guardians at Progressive Field.

CLEVELAND – Orioles manager Brandon Hyde watched Gunnar Henderson hit on the field hours before batting practice, an early session that confirmed everything he knew about the former second-round draft pick. The tools on display. Some of the reasons why he rates so highly among scouts and talent evaluators.

Why he’s the youngest Oriole to debut since Dylan Bundy in September 2012. And the youngest position player since Manny Machado that same year.

“It’s really impressive,” Hyde said. “It’s so physical, so strong, and it’s exciting to have another one of our top prospects here.”

Henderson is least likely to play first base with Ryan Mountcastle entrenched as the starter and Jesús Aguilar going from taxi squad to expanded roster on Thursday.

“We’re going to play him multiple spots in the infield,” Hyde said after writing Henderson’s name at third base on the lineup card. “It’s something he’s been preparing for down at Norfolk, getting a lot of reps. Recent reps at second base, shortstop, third base. He’ll be day-to-day with where we put him in the infield.

CLEVELAND – Gunnar Henderson predicted that he’d reach the majors this year. He set it as a goal before his season began at Double-A Bowie. So confident that he texted it to his girlfriend, Katherine Lee Bishop, who took a screenshot as proof.

Here he is. Perhaps in a location he couldn’t have known about, but on the Orioles roster and starting for them tonight at third base.

“That’s pretty cool to accomplish that,” he said today while standing at his new locker, “but the road’s just starting, so the work keeps on going.”

Henderson had to block out the distractions while concentrating on each at-bat, each ground ball, in order to become the youngest Orioles position player to debut since Manny Machado in 2012.

Tabbed by Baseball America as the No. 1 prospect didn’t exactly quiet the room.

CLEVELAND – The Orioles didn’t wait until Thursdays’ roster expansion to select infielder Gunnar Henderson’s contract from Triple-A Norfolk.

They did it early this afternoon, bringing up Henderson and optioning infielder Tyler Nevin to Norfolk.

Pitcher Denyi Reyes was designated for assignment to create room on the 40-man roster.

Henderson, who’s wearing No. 2, could be in tonight’s lineup against Guardians right-hander Triston McKenzie. We’ll find out later.

The first appearance will allow Henderson, 21, to become the youngest Oriole to make his major league debut since infielder Manny Machado in 2012. Machado was a first-round shortstop who switched to third base. Henderson is a second-round shortstop in 2019 who’s played all four infield positions in the minors, gaining experience on the right side this month.

CLEVELAND – Spenser Watkins retired the first 11 batters tonight and seemed intent on maintaining the recent run of quality starts from the rotation.

To do so, of course, required Watkins to limit the number of runs.

Watkins surrendered two in the fourth inning and three more in the fifth, exiting before the final out, and the offense sputtered again in the Orioles’ 5-1 loss to the Guardians at Progressive Field.

The beginning of another important series for the Orioles produced the third loss to Cleveland in four games this season and lowered their record to 67-61.

Cal Quantrill allowed a leadoff single to Ramón Urías in the second inning, and it was the last Orioles hit. Quantrill retired the last 10 batters he faced after Anthony Santander’s two-out walk in the third.

CLEVELAND – Tyler Wells is getting closer to appearing in games and rejoining the Orioles.

Wells threw about 30 pitches today during a bullpen session at high Single-A Aberdeen, and he’s poised to begin an injury rehab assignment with the IronBirds.

Today’s activity followed the simulated game from a few days ago.

“Felt great after, so positive news there,” said manager Brandon Hyde.

“We’re going to get him into some sort of rehab game if he wakes up tomorrow and feels well. We’re taking it just kind of day-to-day with him right now, but as of right now, it went well and we’re going to continue to progress him.”

CLEVELAND - The Orioles leave Houston after winning two of three games against the team with the best record in the American League, and now they play three games in Cleveland against the leaders in the Central Division.

Yesterday’s off-day actually cost the Orioles a half-game in the wild card race. They’re two behind the Blue Jays for the last spot.

The Guardians won two of three games from the Orioles at Camden Yards on June 3-5. They’ve lost six of their last 11.

Right-hander Cal Quantrill is 10-5 with a 3.59 ERA and 1.203 WHIP in 24 starts. He’s walked 38 batters and struck out 94 in 143 innings.

Quantrill is having his best month in August, going 3-0 with a 2.25 ERA and 0.781 WHIP in five starts. He’s tossed six, seven and seven scoreless innings in three of his last four outings, holding the Blue Jays to one hit in seven frames on Aug. 12.

The Orioles are trying for their second three-game sweep in Houston in two seasons.

The rotation has tied a season high with four quality starts in a row, posting a 1.26 ERA during that stretch. The ERA is 2.25 in the last 11 games.

The Astros have been held to one run in the first two games. Kyle Bradish and Dean Kremer have combined for 15 2/3 innings, after Jordan Lyles completed seven innings on Thursday.

It really does start with starting pitching.

Only 1 ½ games separate the Orioles from the last wild card spot. But they’re facing Justin Verlander today.

Kyle Bradish came up with a nice solution Friday night to the bullpen’s recent struggles that raised concerns about its ability to hold up through the rest of the wild card chase.

Stay on the mound for eight innings and don’t allow any runs.

So simple. Why didn’t anyone else think of it?

Dean Kremer ran with the idea last night, holding the Astros to one run in 7 2/3. All it takes is one person to start a movement.

A fresh right arm arrived to the team Thursday afternoon when the Orioles recalled Rico Garcia from Triple-A Norfolk. Rosters expand to 28 players on Sept. 1, which allows them to bring up another pitcher.

The Orioles wanted veteran starter Jordan Lyles to be durable and dependable. To make each start, push past the middle innings and give his club a chance to win. They sought his leadership on an inexperienced staff.

And they were willing to sign him for $7 million guaranteed with a $11 club option for 2023.

How’s it working out?

“I think he’s exceeded our expectations and what he’s done for us in every way,” says manager Brandon Hyde.

Hyde has gone on record with that opinion multiple times this season, most recently before Thursday’s game.

The challenges keep coming at the Orioles, one after another, contenders leaving them and others waiting right around the corner.

A ninth walk-off win last night is followed by a three-game series in Houston, where the Orioles can visit with former teammate Trey Mancini and try to gain ground in the wild card race.

Last night’s improbable result, a 4-3 win in 11 innings over the White Sox, kept them 2 ½ games back for the last spot.

The Orioles earned their 29^th comeback win, the most since 2017, after Kyle Stowers tied the game with his first major league home run after falling behind 0-2 with two outs in the ninth. Anthony Santander singled in the 11^th for his second career walk-off hit.

The club has registered three consecutive winning months for the first time since April-June 2016.

A clubhouse that’s started to check the standings while it’s in the thick of a wild card race – likely a majority of players, if not universally – knew exactly where it stood tonight before the first pitch.

The Rays won. The Mariners won. Two teams gaining ground ahead of the Orioles.

The outcomes don’t really matter if the Orioles can’t take care of their own business, which is why they glance at the scores and lock in on their opponent.

Jordan Lyles surrendered a first-pitch home run tonight and cruised into the seventh, where the White Sox tied the game on two soft hits and a throwing error. They scored a run in the eighth against Dillon Tate, again doing damage within the bullpen, and came within a strike of winning in regulation. Of retiring the last 13 batters.

Down 0-2 against closer Liam Hendriks, Kyle Stowers hit his first major league home run with a shot to center field that tied the score. A rookie in his seventh major league game, with three hits in 23 at-bats and none in his last 13, handling some of the business.

Tyler Wells threw his second bullpen session today and keeps making progress in his eventual return from a left oblique injury.

Wells is nearing a live batting practice session to get him reacclimated to facing hitters.

“It’s going very well,” Hyde said. “Threw his second bullpen, feels great after. All positive news from there.”

The Orioles haven’t determined Well’s role after he makes it back onto the active roster. Building him back up as a starter will take longer, which could influence them to make him a reliever.

“We’re still going to work some things out,” Hyde said.

The Orioles recalled reliever Rico Garcia from Triple-A Norfolk today to provide a fresh arm for a struggling bullpen. They optioned reliever Louis Head after last night’s game.

The club also optioned reliever Phoenix Sanders after claiming him off waivers yesterday from the Rays. He has three minor league options.

Garcia has appeared in four games with the Orioles and allowed four runs and eight hits in six innings. He has a 2.30 ERA in 14 appearances with Norfolk.

The Orioles will try tonight to win another series and move closer to the final wild card spot. They remained 2 ½ games back after last night’s 5-3 loss to the White Sox.

Kyle Stowers is in right field and Terrin Vavra is starting at second base.

The debate over American League Rookie of the Year is boiling down to Orioles catcher Adley Rutschman and Mariners center fielder Julio Rodríguez. Much of the field is evaporating. They could be one and two, though more than a month of the season remains.

The ballot distributed to qualified members of the Baseball Writers’ Association of America holds three names.

Does Orioles reliever Félix Bautista belong on it?

“Yeah, he’s been unbelievable this year,” said first baseman Ryan Mountcastle.

“Absolutely,” said starter John Means.

First baseman Ryan Mountcastle made a diving stop of Yoán Moncada’s ground ball tonight and outraced him to the bag to record the out and prevent at least one more run from scoring. Elvis Andrus struck out, and Spenser Watkins caught a break only down 2-0 in the first inning.

On many nights in 2022, that play would launch a comeback for the Orioles. Their starter would get on a roll, they’d string together some hits, and the outcome would strengthen the belief that they have the stamina to stay in the wild card chase.

They still feel that way. Their confidence won’t erode. And Watkins didn’t allow another run. But the Orioles couldn’t push past the White Sox, who kept the lead and won 5-3 at Camden Yards.

Austin Hays slugged a two-run homer off Liam Hendriks in the ninth, his 300th career hit, but a fifth attempt to move seven games above .500 failed, dropping the Orioles to 64-59.

Watkins stranded a runner in each of his next four innings and retired the side in order in the sixth on three ground balls. The White Sox hadn’t cashed in much during this series, leaving 27 on base.

Orioles manager Brandon Hyde is breaking out his reverse-splits lineup again tonight with the White Sox starting right-hander Lucas Giolito.

Robinson Chirinos is catching and Adley Rutschman is serving as the designated hitter. Terrin Vavra and Kyle Stowers are on the bench.

Shortstop Jorge Mateo is batting eighth tonight for the 20^th time. He’s batted second once, fifth in three games, sixth in four, seventh in 16 and ninth in 65.

Mateo is slashing .294/.342/.538 with nine doubles, four triples, six home runs, 25 RBIs and 27 runs scored in his last 44 games since July 1, and .317/.355/.574 with seven doubles, two triples, five home runs, 20 RBIs and 20 runs scored in 29 games since the All-Star break. His .929 OPS in the second half ranks 11^th in the American League.

Hyde could elevate Mateo in certain matchups, but he doesn’t want to mess with a good thing.