Hosmer was injured while bunting with two strikes for the second out of the first inning and was taken out of the game. He was replaced by Mitch Moreland, acquired during one of six trades general manager A.J. Preller made in the days before last week’s deadline.
Later in the game, Hosmer was in the dugout with what appeared to be a splint on his left index finger.
Hosmer is batting .288 with eight home runs and 32 RBIs in 34 games for the Padres this season.
The Associated Press contributed to this report.