St. Louis Cardinals right-hander Miles Mikolas exited his start Saturday against the Chicago Cubs with right forearm tightness, the team announced.
The Cardinals placed Mikolas on the injured list Sunday due to the injury.
The 32-year-old was making his first start of the year. The 2018 All-Star had been on the injured list since the beginning of the season due to a shoulder ailment.
The right-hander also missed the entire 2020 campaign with a forearm injury.
Mikolas threw four innings against the Cubs prior to suffering the injury, allowing one run on three hits and one walk while striking out three. Daniel Ponce de Leon took over on the mound for the fifth.
Following the game, Cardinals manager Mike Shildt said Mikolas is undergoing an MRI, according to Katie Woo of The Athletic.
Since returning to the majors in 2018 and inking a four-year contract with the Cardinals, Mikolas authored a 3.46 ERA and 3.76 FIP over 64 starts entering Saturday.
St. Louis recalled Junior Fernandez to fill a spot on the active major-league roster.
