Blackburn felt a cramp in the back of the shoulder Saturday against the Texas Rangers, and he left in the sixth inning. General manager Terry Ryan said Sunday that Blackburn was "a little bit stiff" but otherwise fine.
Ryan said the Twins will closely monitor Blackburn this week and be cautious about his condition. But he says "all indications are that he's going to be OK" to start Thursday in New York against the Yankees.
Right-hander Jason Marquis will join the rotation Wednesday after a couple of tuneup starts in the minors. If Blackburn is unable to pitch as scheduled, the Twins could use right-hander Anthony Swarzak.