MINNEAPOLIS - CC Sabathia's rehab had been going smoothly, with Wednesday's minor-league outing for Double-A Trenton the most encouraging sign yet. But that came to a dramatic halt Thursday. Joe Girardi said Sabathia woke up with "swelling'' in his right knee and that he will be shut down indefinitely.

"They did another MRI and we're waiting to see what the next step is,'' Girardi said before Thursday night's game against the Twins. "I can't tell you how long he's going to be shut down.''

Sabathia, 33, had not been pitching particularly well when he went on the disabled list May 11 with inflammation in his right knee. He was not impressive in two rehab starts but came through them feeling healthy.

Sabathia gave up his share of hard-hit balls in 32/3 innings Wednesday night, allowing five runs (three earned), five hits and a walk. But the stadium radar gun had his fastball peaking at 94 mph, the fastest it's been in two years. There was skepticism regarding that number, but a scout in attendance said his gun had similar readings.

Afterward, Sabathia said, "Health-wise, I'm ready to go.''

That changed Thursday.

"He said nothing during the game about it and he woke up today [feeling sore], that was the report I got,'' Girardi said. "Today it was swollen and similar to what he had been experiencing before.''

Sabathia's knee began to act up in early May, and he tried to pitch through the problem before it ballooned after a May 10 start in Milwaukee. He went on the disabled list the next day. Two days after that, he visited Dr. James Andrews, who diagnosed what general manager Brian Cashman called "degenerative changes'' in his cartilage.

Sabathia received an injection of cortisone and stem cells, a treatment the team hoped would lead to a return shortly after the All-Star break.

"It's not what you want, but you have to deal with it,'' Girardi said. "We were hopeful that the swelling would stay away and that he would be in our rotation fairly soon, but it doesn't appear that's going to happen.''

Even if the lefthander's rehab had continued without setbacks, the Yankees had no idea what kind of pitcher they would be getting back. He was 3-4 with a 5.28 ERA, looking like the pitcher who was 14-13 with a 4.78 ERA last season, the worst of his career.

Regardless of Sabathia's condition, Brian Cashman's charge before the July 31 trade deadline was going to be the same: find starting pitching.

"Even if you get him back, what are you getting?'' an opposing team's scout said. "At best a No. 4, and maybe not even that.''

But the Yankees still would prefer a struggling Sabathia to the rookies occupying the back end of their rotation. Vidal Nuño and Chase Whitley have done well at times, but neither provides the near assurance of at least six innings every start, as Sabathia generally did. That is no small thing for a bullpen that far too often has been called on to get 10 or more outs.

"I don't think our organization's thinking ever changes. I think they're always looking to better our team no matter what,'' Girardi said. "And I'm sure we've been scouting players just like every other team has. I think the approach will be the same because when someone's injured, you can never count 100 percent that they're coming back.''