PHILADELPHIA -- It remains unclear if Phillies ace Cole Hamels will pitch next week in St. Louis.

Hamels, who suffered a mild sprain of his left ankle Tuesday against Washington, threw a bullpen session Saturday afternoon at Citizens Bank Park. Phillies general manager Ruben Amaro Jr. said Hamels threw OK, but "felt some soreness on a couple pitches when he dragged his foot."

Hamels is scheduled to pitch Monday, but that is very unlikely to happen. Amaro indicated Phils right-hander Brett Myers will pitch Monday instead. That means if Hamels is healthy enough to pitch, he would pitch Tuesday against the Cardinals.

"Tuesday we'll need a starter," Amaro said. "If it's Cole, great. It may not be. If it's not, it might be [J.A.] Happ or someone else."

"He could probably pitch if he just stood on the mound and didn't do anything but pitch, but that's not how it works," Amaro added. "We've got to make sure we see some other things, whether it's coming off the mound and fielding and those sorts of things. Those are the things we're still pretty concerned about. We don't want t put him in a position to re-injure it."

Amaro said they could wait as late as Monday before they make a decision on Hamels. Amaro said a trip to the disabled list for Hamels is possible, but "just from what he's done today, how he threw today and how he felt, we'd like not to have to do that, but if he doesn't progress real well over the next few days and we don't feel like he's going to make a start, that's something we would consider."

Hamels was unavailable to comment.