Blackburn exited his April 14 start with right shoulder stiffness but reported back to the visitor's clubhouse at Tropicana Field with no soreness, saying everything felt loose and ready to go Tuesday.
"I couldn't feel anything at all, so everything seems to be pretty loosened up," Blackburn said. "It's good."
With Blackburn taking a spot in the rotation, manager Ron Gardenhire said Anthony Swarzak will join the bullpen and should be available to pitch in relief Monday. The Twins are carrying 13 pitchers on the 25-man roster but won't make a roster move until they see how Blackburn bounces back from Tuesday's outing, most likely coming on Thursday's off-day.
"Obviously no guarantees. We won't know anything until I've been out there a couple times. Just going off the bullpens I've thrown, I felt great," Blackburn said. "Every day's been such an improvement. I feel like I have to have a positive reaction from the way it's responded to all the treatments.
"Just because you don't feel something being sore or tight doesn't mean it doesn't exist. I think in the future, I'll be more on top of keeping everything stretched out. It could potentially help me throw better."