Kepler, 22, is having a breakout season, hitting .335/.410/.534 with three homers, eight triples, 22 doubles and 34 RBIs in 65 games. Kepler, who has seen time at first base and in the outfield, also has 12 stolen bases and 43 runs scored.
"I'm sure he's disappointed, like all of us are," said general manager Terry Ryan. "We would have certainly liked to have seen him in the game. But you have to be healthy enough to take the post, and he's not."
Kepler, a native of Germany, is Minnesota's No. 14 prospect, according to MLBPipeline.