Boxberger left Saturday's game against Cincinnati due to an undisclosed injury, Bobby Nightengale of The Cincinnati Enquirer reports.
Boxberger entered with the Brewers leading 3-2 in the bottom of the eighth, but he quickly exited after allowing a game-tying homer to Jonathan India. Per Nightengale, the right-hander's velocity was down. Milwaukee will likely provide an update following Saturday's game, and until then, the reliever can be considered day-to-day.