Tampa Bay Rays left-hander Shane McClanahan left his final spring training start against the Boston Red Sox on Saturday with triceps tightness to his pitching arm.

McClanahan will undergo imaging and testing to determine the severity of the injury, the team announced.

Coming off Tommy John surgery, McClanahan has not appeared in a major league game since August 2023.

McClanahan pitched 2 innings and surrendered one hit and one walk, striking out three and facing nine batters. But after a pitch to Red Sox prospect Kristian Campbell, McClanahan grimaced in obvious pain as his left arm dropped to his side, and he immediately called for a member of the training staff.

Manager Kevin Cash earlier named McClanahan, 27, as the Rays' starting pitcher for the March 28 season opener against Kyle Freeland and the Colorado Rockies. That debut date is now in serious doubt.

McClanahan started Opening Day for the Rays in both 2022 and 2023, and he threw 10 scoreless innings, combined.

This spring, the Rays limited the work for McClanahan. He entered the game on Saturday having started two games and throwing 4 scoreless innings with five strikeouts and one walk.

After three major league seasons, McClanahan has a record of 33-16 with a 3.02 ERA in 74 games. The two-time All-Star has thrown 404 innings with 456 strikeouts.

--Field Level Media contributed to this report.