Lucroy got hurt after during Monday's 6-1 loss to Cincinnati when a foul tip caromed off his foot. He was placed on the 15-day disabled list immediately after the game.
The injury news only got worse on Tuesday for struggling Milwaukee.
Manager Ron Roenicke said Tuesday starting second baseman Scooter Gennett was placed on the DL after cutting his left hand in the shower after Sunday's game in Pittsburgh. The move was retroactive to Monday.
Milwaukee had the worst record in the majors at 2-11 going into Tuesday's game against the Reds.
The offense was struggling even before the injuries to Lucroy and Gennett. Outfielder Carlos Gomez is on the disabled list with a strained right hamstring.
"It's hard, but like I said we weren't winning and scoring runs when we had everybody," Roenicke said. "So hopefully some of the different guys I put in there today, those guys are hot."