The injury that forced right-hander Hunter Dobbins out of Friday night’s game after just 1.2 innings is a right ACL tear, the Red Sox announced Saturday morning. His season is likely over.

The rookie was in visible discomfort after rushing to cover first base to make the second out of the inning. Though he initially struggled to put weight on his right leg, it took several minutes of deliberation with manager Alex Cora and a trainer to determine whether the rookie needed to leave the game. They walked back to the mound, where Dobbins threw a practice pitch to test his body, only for the group to decide that he should exit.

Dobbins was undergoing an MRI as the Red Sox won their eighth game in a row, on a walk-off two-run homer by Ceddanne Rafaela. Friday was Dobbins’ first start since June 20, after which he went on the injured list with an elbow strain.

Right-hander Richard Fitts, whom the Red Sox optioned earlier this week in order to add Dobbins back to the rotation, has been recalled from Triple-A Worcester.