Pavano met with team physician Dr. Dan Buss in Minneapolis on Monday and underwent an MRI exam, which revealed a right anterior capsular strain. It was his second MRI exam this season, as he also had one on May 11 that revealed a similar strain.
"We'll let him rest a little bit, and when he's ready, then we'll get him on a throwing program and he'll work his way back to pitching," assistant general manager Rob Antony said. "No timetable on it. He'll do some exercises and he'll continue to work out and do the other stuff, but until we can calm down the strain and there's no pain, we can't start the throwing program."
Pavano said Saturday that the injury starts to affect him once he gets to about the 60-pitch mark. He's struggled to fight through the injury, as he's 1-4 with an 8.25 ERA in his past five starts, and has a 6.00 ERA in 11 starts this season.
There's still no timetable for his return, but there's a chance he could be out at least six weeks, as he will need to build up his pitch count after resting his shoulder.
Blackburn, meanwhile, was reinstated to the 25-man roster after the sinkerballer finished a rehab assignment at Triple-A Rochester. Blackburn, who had been on the DL with a left quad strain, will pitch Wednesday in Kansas City.
He saw his last outing cut short due to rain on Sunday, as he threw just 27 pitches over 2 1/3 innings before the game was postponed. In two rehab outings, he allowed four earned runs on six hits in six innings.
"We actually wanted [Blackburn] to throw some more innings down there, but this was the right thing to do," Twins manager Ron Gardenhire said. "He had two starts and had a 90-plus-pitch bullpen [session] in Minnesota. So he's been throwing quite a bit. His legs feel great. He feels healthy. His arm feels great. So now we'll see how he does out here."