Bummer (knee) was placed on the 15-day injured list as expected Monday.
Bummer hadn't pitched since Friday, so the transaction can be backdated two days, leaving him eligible to return May 22. It's not entirely clear whether or not he'll be able to do so, especially with the White Sox now referring to his injury as a strain rather than merely soreness. Joe Kelly (biceps) returned from the injured list to take his place in the bullpen.