Lauer landed on the injured list for undisclosed reasons Saturday, Adam McCalvy of MLB.com reports.
Clubs across the league have provided minimal details on several injured-list assignments due to privacy issues concerning COVID-19, though Lauer was reportedly battling a non-coronavirus illness earlier in camp. The lefty, who was acquired in a trade with the Padres back in November, is battling for a spot in the back of the Brewers' rotation, though his lost time could lead to him opening the season in the bullpen.