Clemens tweaked his hamstring while running Thursday and originally was rescheduled from today to tomorrow. Andy Pettitte will now start tomorrow's series finale against Toronto on regular rest, and Clemens will start the series opener at Tampa Bay.

"We hope he can pitch on Tuesday; we think he will," Yankees manager Joe Torre said today. "We're putting him back in his slot, which has been behind Andy all year."

Clemens has pitched just once since Sept. 3, sidelined at first by a tender right elbow that required two cortisone shots. The 45-year-old right-hander pitched six innings at Boston on Sept. 16, allowing an unearned run and two hits in six innings.

The seven-time Cy Young Award winner threw a side session this morning in the Yankee Stadium bullpen. Clemens said his leg felt "a little bit more fatigued than normal."

"I felt really good yesterday," Clemens said. "It feels a little different today because I've had a lot people digging at it and doing things to it."

He said trainers Gene Monahan and Steve Donohue were pleased with his progress.

"I think that Geno and Steve consider it good that two spots showed up finally, which means the blood is coming to the surface," Clemens said.

Clemens, 6-6 with a 4.18 ERA, said he'll likely pitch with a wrap around his leg in his next start. He has at most two starts left before the playoffs, when he is likely to be part of a rotation with Chien-Ming Wang, Pettitte and Mike Mussina.