Teammate Jace Peterson was also added to the injured list because of contact tracing.
Yelich has mild symptoms and will miss a minimum of 10 days, via Will Sammon of The Athletic.
During the shortened 2020 season, Yelich saw his performance drop compared to his first two years with the Brewers when he won a National League MVP and then finished runner-up. He batted .205 and slugging .430 in 58 games.
A small sample can yield somewhat skewed numbers, but the two-time All-Star has continued to struggle into 2021. Through 67 games, he has a .235/.382/.367 slash line to go along with six home runs and 28 RBI.
Yelich battled back trouble, which landed him on the injured list in May and can help partially explain his relative lack of power.
Despite that, the Brewers entered Tuesday in first place in the National League Central at 58-42, seven games up on the Cincinnati Reds. A fourth straight trip to the postseason is well within reach.
The pitching staff has been a big reason for the team's success. Yelich's absence will put even more of the burden on Milwaukee's arms since the lineup will likely take a step backward.