Gennett cut his hand in the shower, he wrote Monday on Instagram.
Elian Herrera, a 30-year-old ultilityman with 140 games of major-league experience, was called up from Triple A to take Gennett's spot on the roster.
Gennett said he cut himself on a piece of metal while showering after Sunday's loss to the Pittsburgh Pirates. He had the cut closed with stitches. Manager Ron Roenicke was initially unsure whether Gennett would be placed on the disabled list.
"We have a decision to make with how many days that's going to be," Roenicke said Monday, according to the Milwaukee Journal-Sentinel. "There's always that chance (to go on the DL). Obviously, we're at a spot now where we don't want to play short. If we feel like we need to, then that's what we'll do."
Gennett, 24, has been Milwaukee's starting second baseman since July 2013. He batted .324 in 69 games as a rookie in 2013 and .289 in 137 games last season. He has six hits in 29 at-bats so far this season.
The Brewers are 2-10, their worst start in franchise history.
- Dan Gartland