Alexander was placed on the 10-day injured list with left shoulder inflammation Thursday, retroactive to May 3.
Alexander was dealing with shoulder soreness in Tuesday's doubleheader against the Cubs, and he'll now miss additional time after he was diagnosed with inflammation. It's not yet clear when the left-hander will be able to return to the mound, but right-hander Joe Kelly (shoulder) was reinstated from the 10-day injured list in a corresponding move.