The injury first occurred Saturday when he lost his footing rounding the bases, causing him to miss Sunday's game. The team hopes the injury is limited to 10 days before he can return.
However, the injury ended up being serious enough to make the roster move.
With the Red Sox already dealing with a team-wide flu epidemic, depth has become a serious issue. Steve Selsky played center field Sunday against the Detroit Tigers and could earn more playing time going forward.
Bradley was one of Boston's breakout stars in 2016, earning his first All-Star appearance while hitting .267 with 26 home runs and 87 RBI, plus above-average defense. His absence will be noteworthy with upcoming series against Boston's AL East foes, the Baltimore Orioles and Tampa Bay Rays.