Another day, another addition to the Orioles’ injured list.

On Saturday it was Ryan Mountcastle, who was placed on the 10-day IL with a right hamstring strain. On Friday night, Mountcastle stole home in the sixth inning of the Orioles’ 2-1 win over the White Sox and then exited with hamstring discomfort. An MRI on Saturday morning showed the strain, but interim manager Tony Mansolino said he did not know the severity of it yet.

“Hopeful that it’s not too bad,” Mansolino said. “We’ll probably find out more later today or tomorrow.”

In his place, the Orioles called up No. 2 prospect Coby Mayo. They also selected the contract of Jordyn Adams, giving them an additional outfield option because they are without Cedric Mullins (right hamstring strain), Tyler O’Neill (left shoulder impingement), Ramón Laureano (left ankle sprain) and Colton Cowser (left thumb fracture).

“Having all those guys down, it’s not helping us,” Mansolino said. “But we’ve got good guys in the building, and hopefully they can help us win another game tonight.”

The team also designated catcher Chadwick Tromp for assignment.

The Orioles have 12 players on the injured list but should be getting some back soon. Cowser and Jordan Westburg (left hamstring strain) are on rehab assignments with Triple-A Norfolk, while O’Neill, Laureano and Gary Sánchez (right wrist inflammation) took batting practice on the field Saturday.

Mountcastle wasn’t having his best season — he’s hitting .246 with just two home runs — but, as a two-time Gold Glove finalist at first base, his defense gives him value to this team.

Mayo — who plays first and third — is back with the team for the second time this season after making his debut last year. He has five hits in 53 major league at-bats. Defense has never been his strong suit, but Mansolino, who spent a lot of time working with Mayo in his previous role as the infield coordinator, has seen improvement.

Mayo will be the designated hitter Saturday.

“I think he’s gotten better,” Mansolino said. “I think he is trending upward. I think he is doing better, but it’s something that he needs to continue to work hard at.”

Adams, a first-round pick by the Angels in 2017, made his MLB debut in 2023 and played 28 games across that season and the next for Los Angeles, hitting .176 with a .426 OPS. He was designated for assignment in April and signed a minor league deal with the Orioles in December that did not include a nonroster invitation to major league spring training.

He can play all three outfield spots, which will give the Orioles a little flexibility with Dylan Carlson and Heston Kjerstad, who can only play the corners, the only other true healthy outfielders on the roster. Adams will likely be used as a late-inning defensive replacement.

The Orioles could have also brought up a prospect, such as Jud Fabian, who was performing better at the plate in Triple-A than Adams was. However, with Cowser expected back next week, this likely will be a short stint for Adams, and the Orioles typically like to wait to call prospects up until they can give them steady playing time.