Blackburn is missing his scheduled start against the Yankees on Thursday because he's been dealing with shoulder stiffness stemming from his outing against the Rangers on Saturday.
But he took a positive step forward by playing catch from 120 feet on Wednesday, and even threw a few breaking balls from 90 feet without any discomfort.
"I felt good," Blackburn said. "I didn't feel anything in that original spot of tightness or anything. I've still got some tender areas, but we're also doing a whole lot of probing and exercises I'm not used to doing. So I went out there and threw, and it felt great. I feel every day is a pretty good improvement."
Blackburn's next step is a light bullpen on Friday and a full bullpen on Sunday to get ready for Tuesday's start.
"He didn't feel anything and there were no limitations whatsoever," Twins manager Ron Gardenhire said. "He basically told us he really believes 100 percent he'll start Tuesday."