BALTIMORE -- Orioles first baseman Ryan Mountcastle has a broken fourth metatarsal bone in his left foot and will go on the injured list.
"It's tough," manager Craig Albernaz said after Baltimore's 6-2 victory over the San Francisco Giants on Sunday.
Albernaz did not offer a timetable for Mountcastle's return.
Mountcastle, 29, left Saturday's game with left foot pain after stumbling running from first base to second on a double. He is hitting .286 with an RBI in eight games this season. He saw sporadic playing time with Pete Alonso as Baltimore's regular first baseman.
Mountcastle was limited to 89 games last season, missing more than two months because of a strained right hamstring. He hit .250 with seven homers and 35 RBIs in 2025.
Also, outfielder Tyler O'Neill is on the IL for the Orioles with a concussion.
Albernaz said Sunday that O'Neill was ill for a week and fainted Thursday while dealing with dehydration.
"As he was getting worked on to play, he just felt dizzy," Albernaz said. "We're making sure he's good to go."
Albernaz also said there was "encouraging news" from catcher Adley Rutschman's MRI exam. Rutschman was placed on the 10-day injured list Saturday with left ankle inflammation.
Information from The Associated Press was used in this report.
