DETROIT -- Tigers left-hander Dontrelle Willis is on track to go on a Minor League rehab stint next week as he works his way through a hyperextended right knee.

Willis threw what manager Jim Leyland called a solid side session Thursday morning in which the lefty felt some limited pain in the knee in early pitches, but was progressively better as the session continued. He'll throw a simulated session to hitters Saturday afternoon; if that goes well, he'll probably throw another bullpen session with the team on the road in New York before reporting to Triple-A Toledo for a start later next week.

"I would assume Dontrelle Willis will be pitching in a [Minor League] game next week, maybe a week from today," manager Jim Leyland said.

Willis is in favor of a rehab stint. He was also very much in favor of a simulated outing beforehand.

"I think the telling thing is just for me being able to get to [pitch to] hitters," Willis said, "because the effort level's a little different as opposed to [bullpen sessions]. If I can get back out there and really get back out front, then I'll feel more confident. But I feel more confident now than before I got hurt, as far as my strength."

For someone who had never been on the disabled list in the Major Leagues until he hurt his knee slipping off the mound against the White Sox on April 11, Willis has shown some relative patience in the process. He has worked regularly with strength and conditioning coach Javair Gillett to strengthen the knee, and he has repeatedly said that he's willing to do a rehab stint before coming back, though he has the right to decline it if he wishes.

"Javair and [the athletic training staff] have done a great job of getting on me," Willis said. "This is my first time being hurt, so I'm kind of stubborn about getting back there, getting the proper treatment. But they've done a great job of staying on top of me."

Armando Galarraga will make his third start for the Tigers in Willis' place on Saturday. He has won both of his previous outings to take the team lead in victories, though reliever Clay Rapada tied him with a victory Wednesday.