A day later, Bummer was placed on the 10-day injured list with a left biceps strain, the team announced Saturday. Bummer's injury is arguably the White Sox's most detrimental yet, as he had a terrific 2019 and had posted a 1.23 ERA in seven appearances early on this season. Bummer has been as reliable as it gets in high-leverage situations over the past two seasons.
It's unclear how long Bummer could be out.
"We do not know the extent of the injury," manager Rick Renteria said of Bummer. "Hopefully it's not anything significant."
In addition to Bummer, White Sox right-hander Reynaldo Lopez (shoulder) and left-hander Carlos Rodon (shoulder) are on the 10-day injured list. Right-hander Jimmy Lambert (forearm strain) is on the 45-day injured list, meaning he's unlikely to return in 2020.
In corresponding moves Saturday, the White Sox also recalled right-hander Zack Burdi from their Schaumburg camp, purchased the contract of right-hander Drew Anderson from Schaumburg and designated right-hander Brady Lail for assignment.
Burdi, 25, had a 4.31 ERA in four minor league seasons in the White Sox's farm system. The White Sox selected him in the first round of the 2016 amateur draft. He threw one scoreless inning in his MLB debut Saturday as the White Sox lost 7-1 to the Indians.
Anderson, 26, signed with the White Sox last November. He has a 3.52 ERA in eight minor league seasons, all in the Phillies organization. He has made nine appearances in his MLB career, posting a 7.71 ERA across 21 innings.