White Sox manager Tony La Russa said after Sunday's 3-2 win over the Red Sox that Bummer is slated to land on the injured list with a sore knee, Daryl Van Schouwen of the Chicago Sun-Times reports.
Bummer presumably picked up the injury during his most recent relief appearance Friday, when he tossed a scoreless inning en route to notching his seventh hold of the season. The White Sox will likely make the transaction official prior to Monday's series opener with the Guardians.