Orioles place two outfielders on IL, activate Ryan Mountcastle

The Orioles placed two outfielders on the injured list Friday and reinstated Ryan Mountcastle from the 60-day IL.

Jul 2, 2025; Arlington, Texas, USA; Baltimore Orioles left fielder Colton Cowser (17) celebrates after hitting a double against the Texas Rangers during the game at Globe Life Field. Mandatory Credit: Jerome Miron-Imagn Images | Jerome Miron-Imagn Images

As one major leaguer returns from the injured list, the Baltimore Orioles lose two more.

Hours before Friday’s series opener against the Athletics, the Orioles placed outfielders Tyler O’Neill (right wrist inflammation) and Colton Cowser (concussion) on the injured list. In corresponding moves, the club reinstated first baseman Ryan Mountcastle from the 60-day injured list and recalled outfielder Jordyn Adams (.565 OPS in Triple-A) from Norfolk.

We have made the following roster moves: pic.twitter.com/JDV4dSG6u3

— Baltimore Orioles (@Orioles) August 8, 2025

O’Neill, 30, previously left Tuesday’s game with right wrist discomfort. Interim manager Tony Mansolino said he is cautiously optimistic that O’Neill’s absence will be minimal, though the outfielder is still “sorting through opinions” from the MRI.

The eight-year veteran has had multiple stints on the injured list during his first season in Baltimore, appearing in just 43 games so far. He homered in five of his last eight games entering Tuesday’s action but is slashing .210/.293/.434 with eight home runs, 23 RBIs, and two stolen bases on the year.

Cowser, 25, suffered the concussion when he went to catch a fly ball hit by Harrison Bader and collided with the left-field fence during the sixth inning of Wednesday’s win in Philadelphia. Mansolino said Cowser’s symptoms developed after the game ended but described the injury as “very mild.”

In 56 games this season, Cowser has hit .213/.279/.401 (.680 OPS) with nine home runs and 22 RBIs. Last year’s AL Rookie of the Year runner-up missed more than two months earlier this season with a fractured left thumb.

Mountcastle Returns

May 11, 2025; Anaheim, California, USA; Baltimore Orioles first baseman Ryan Mountcastle (6) hits a run-scoring single in the fifth inning against the Los Angeles Angels at Angel Stadium. Mandatory Credit: Kirby Lee-Imagn Images | Kirby Lee-Imagn Images

For the first time since late May, the Orioles have penciled Ryan Mountcastle into their starting lineup.

Mountcastle, 28, batted .246/.280/.348 (.628 OPS) with 13 doubles, two home runs, and 15 RBIs through his first 200 plate appearances this season. He was initially expected to rejoin the team during their previous series in Philadelphia, but the Orioles decided to give him a few extra days to rehab from a Grade 2 hamstring strain.

Before landing on the injured list on May 31, Mountcastle had been heating up offensively, batting 7-for-12 with three doubles in his last three games. The six-year veteran picked up right where he left off during his minor league rehab assignment with Triple-A Norfolk, going 12-for-31 (.387) at the plate with three home runs, four doubles, and 10 RBIs in nine games.

Mountcastle stays hot with a two-run double! https://t.co/K9l01LbWVT pic.twitter.com/QtCT7cPanI

— Norfolk Tandangs (@NorfolkTides) August 7, 2025

Mountcastle will bat fifth and start at designated hitter Friday. He was a Gold Glove finalist the past two seasons, finishing 2024 with a .997 fielding percentage, a 1.8 Ultimate Zone Rating (UZR), and tying for the American League lead at his position with eight defensive runs saved.

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Despite Mountcastle’s strong defensive reputation, Mansolino plans to move forward with 23-year-old Coby Mayo as the primary first baseman for the final two months of the season.

“Without a doubt, the lion’s share of first-base work will go to Coby,” Mansolino said Friday. Since being recalled in place of Mountcastle, the No. 2 prospect has posted a .643 OPS over 42 games and is credited with -2 Outs Above Average defensively.