Schwarber still hasn't made his debut for the Red Sox since being acquired prior to the July 30 Major League Baseball trade deadline, initially due to a serious hamstring injury.
Last week, Schwarber reportedly suffered a groin injury "setback" while rehabilitating for the Red Sox on the field during the team's series in Detroit, the Athletic's Jen McCaffrey reported at the time.
Schwarber, 28, was acquired in a trade with the Washington Nationals and initially expected to be reactivated within the next "week or so" at the time of the late July move, ESPN reported.
The former World Series champion was one of baseball's best hitters during the month of July, hitting 16 home runs and recording a 1.122 OPS prior to his injury.
Schwarber, who is currently signed to a one-year, $10 million contract, has a .253 batting average with 25 home runs and 53 RBI, while coming off his first career All-Star appearance, in 2021.
Boston has found itself in a slump recently, losing eight of its last 10 games to fall out of first place in the American League East as the rival New York Yankees inch within 2.0 games of the second Wild Card play-in spot.