Nick Blackburn has been dealing with more than a sore left quadriceps this season.

After his second start, the Twins righthander began having problems with his shoulder, leaving one start early because of cramping. On April 30 against the Angels, Blackburn battled pain in his rib cage area and still has no idea why it happened. Then he came down with left quad problems earlier this month and eventually landed on the disabled list. He felt pain whenever he landed on his left leg during his delivery.

Blackburn believes his problems are behind him now. He threw a 90-pitch bullpen session Saturday, and he will head to Class AAA Rochester for two rehabilitation starts, the first Tuesday on a 75-80 pitch limit. If all goes well, he will rejoin the Twins after that second start Sunday.

"The majority of my starts this year I've started off feeling fine, even if I struggled to find the strike zone early on," he said. "Pitches were sharp, there's good movement, then each time out there something's causing me to hold back, stopping my mechanics.

"It will be good to move on and get past everything and go on."

Blackburn looked and sounded upbeat for someone who is 1-4 with an 8.37 ERA. He said he knows his numbers are bad but is very confident that he will turn his season around.

"I'm actually exited to be going to get this work done, get back here and start helping out," he said.

Delayed loss The start of Saturday's game was delayed 21 minutes by rain. The game was then halted for 42 minutes in the sixth inning. At the time, the Twins had runners on first and third with out and Josh Willingham facing Detroit starter Max Scherzer.

Thanks to the delay, the Tigers brought in reliever Octavio Dotel, who struck out Willingham and got Justin Morneau to pop out to end the inning.

"The guys we've got coming up, you feel good about," Twins manager Ron Gardenhire said. "That's a big situation and the rain stopped us. I don't know who has the advantage, the pitcher coming in or the hitter."

Marquis to be released Twins General Manager Terry Ryan was unable to find a team willing to deal for Jason Marquis, so he placed the veteran righthander on release waivers.

If any club claims him before Monday (release waivers last 48 hours) that team would assume Marquis' $3 million contract. That's unlikely, so Marquis will probably be officially released Monday and free to sign for any club for the major league minimum, with the Twins on the hook for the balance of his contract.

Etc. • Scherzer, who struck out 15 in his previous outing, struck out nine Saturday. "Our at-bats were pretty decent," Gardenhire said. "He's going to strike people out."

• Anthony Swarzak, who gave up six earned runs over 3 2/3 innings on Friday, continued to battle the flu Saturday and was sent home to recover.

• Alex Burnett, who has a slightly sore elbow, threw in the bullpen and felt good. So he will remain in the bullpen queue.

• Scott Baker and his wife, Leann, are the proud parents of a new baby girl. Annalee Grace Baker was born Friday night, weighing 5 pounds, 7 ounces.

• Righthanded reliever Carlos Gutierrez, the 2008 first-round draft pick who hasn't pitched since April 13 for Class AAA Rochester because of shoulder problems, was activated from the disabled list and has returned to the Red Wings.