PHILADELPHIA -- Phillies Cole Hamels had been scheduled to throw a bullpen session Friday afternoon at Citizens Bank Park.

He did not.

Philadelphia said Hamels, who suffered a mild sprain to his left ankle Tuesday against Washington, did not throw for a couple reasons: First, the Phillies did not want him throwing in the rain. Second, they wanted to give him an extra day to rest.

They said he could throw in the bullpen Saturday.

"If he's doing fine," pitching coach Rich Dubee cautioned. "We'll see where he's at."

If Hamels does throw in the bullpen Saturday and if it goes well, Philadelphia manager Charlie Manuel said Hamels could start Tuesday against the St. Louis Cardinals at Busch Stadium, one day later than he originally had been scheduled to pitch.

"We're trying to give him a little extra time," Dubee said.

Hamels was unavailable for comment.

"We'll probably know for sure after tomorrow," Manuel said. "If he's got pain and stuff like that, more than likely, we're not going to pitch him at all."

Catcher Carlos Ruiz, who has been on the disabled list since April 11 with a strained right oblique, continued his rehab assignment Friday with Triple-A Lehigh Valley. Manuel said it is a possibility that Ruiz could be activated as early as Saturday.