Ryan Brasier was taken to a Fort Myers hospital Friday after being struck in the head by a line-drive while pitching in a simulated game.
Red Sox manager Alex Cora told the media Friday that Brasier was in stable condition and would be staying in the hospital for observation.
The outing was the last step before Brasier was scheduled to begin his rehab assignment in the minor leagues, with the Red Sox planning to fly the pitcher to Boston Saturday.
The setback was the latest in a long list of obstacles thrown Brasier's way since the conclusion of last season.
The day before Thanksgiving Brasier fractured the fifth metacarpal on his throwing hand while working out. He then missed time early in spring training to tend to a personal matter back at his home in Texas.
Then, midway through March, Brasier tore a muscle in his left calf, resulting in the delay in joining the big-league team.
The righty is viewed as a potential solution to what has been an up-and-down late-inning bridge to closer Matt Barnes. For the final 1 1/2 months of 2020 the pitcher was the most consistent reliever the Red Sox had, totaling a 1.89 ERA in his final 18 appearances.