So much for Michael Leighton being ready to practice Thursday.

One day after making that announcement, Flyers general manager Paul Holmgren revealed Tuesday that his No.1 goalkeeper would miss a month with a bulging disk in his lower back.

Holmgren also said in Tuesday's conference call that forward Ian Laperriere is out indefinitely with post-concussion symptoms.

On Monday, Holmgren said that an MRI showed that Leighton had a lower back strain that the organization was concerned about. But, according to the general manager, Leighton saw doctors Monday night and Tuesday morning. That's where it was revealed that he actually has a bulging disk.

Leighton suffered the injury in the third period of Friday's 4-3 shootout exhibition victory over the Maple Leafs in Toronto. The 29-year-old was removed after the overtime session and replaced by backup Brian Boucher for the shootout.

"Right now we think that time period is a month just to let everything settle down," Holmgren said of Leighton's injury. "He's actually in here working out today and doing some other stuff. It's uncomfortable when that happens, and that's what he's dealing with right now.

The general manager added the injury is a little more dicey for goaltenders than regular players because goaltenders are bent over all the time in net.

Holmgren added that Laperriere has been dealing with post-concussion symptoms since last season. The right winger will have an MRI Tuesday and will fly to Pittsburgh to see a doctor Friday. Laperriere will visit the same specialist he saw last season after blocking a shot with his face in Game 5 of the Eastern Conference quarterfinals against the New Jersey Devils.

Contact staff writer Keith Pompey at 610-313-8029 or kpompey@phillynews.com.