Hamels, who suffered a mild sprain to his left ankle Tuesday, is scheduled to throw a bullpen session before Friday night's game against the New York Mets at Citizens Bank Park. Lidge, who has not pitched since Saturday because of inflammation in his right knee, also is scheduled to throw in the bullpen.
If Hamels can throw off the mound Friday and feel good in the process, he could make his scheduled start Monday against the Cardinals at Busch Stadium.
"We're still hopeful he'll make his next start," Phillies general manager Ruben Amaro Jr. said. "He might have a little bit more swelling [Wednesday], but it's not a lot."
Phillies pitching coach Rich Dubee said they have some flexibility with Hamels, if he is unable to throw Friday. Because of a day off Thursday, the Phils do not need a fifth starter again until Tuesday in St. Louis.
In other words, Philadelphia could push back Hamels a day.
"If he doesn't make his bullpen that doesn't mean he won't pitch," Phillies manager Charlie Manuel said.
Hamels could throw a bullpen Saturday if he is unable to throw Friday and still make his scheduled start. Hamels was receiving treatment on the ankle Wednesday afternoon and was unavailable to comment.
Lidge said if he can throw off the mound Friday and feel good, he could pitch that night against the Mets.
"That's where I'm really crossing my fingers," Lidge said. "That's the big day."
Lidge has had inflammation in his knee, the same knee that required two surgeries before the 2008 season, since the Phillies played in Colorado earlier this month. He received a cortisone shot April 20, but the sentiment with the Phils is that the knee didn't get enough time to rest -- Lidge pitched last Thursday against the Brewers and again Saturday against the Marlins -- to knock out the inflammation.
Lidge threw off flat ground Wednesday and said it went well.
"Obviously, it's not the same as pitching in a game," Lidge said. "It's still day-to-day."
The Phillies remain hopeful with both, although Manuel isn't making any predictions, particularly with Hamels.
"If I could answer that, son, I wouldn't be sitting here today," Manuel said. "I'd be somewhere else. I don't know where I'd be, but I guarantee if I was that good, I'd be somewhere else."
Todd Zolecki is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.