The Flyers, who are closer to having the NHL's worst record than they are to a playoff spot, will have to play the next two weeks without gifted goalie Steve Mason.

That's how long general manager Ron Hextall estimated Mason will be sidelined because of an injury he suffered Saturday in the first period of the Flyers' 3-1 loss to Boston.

The 26-year-old goalie appeared to injure his right knee, although the Flyers say that it is a lower-body injury.

Mason is expected to miss six games and probably won't play again until after the all-star break. Hextall said Sunday that this was a new injury, "independent" of other ailments that have bothered Mason.

Mason, whose .933 save percentage in even-strength situations is sixth among goalies who have played at least half of their teams' contests, is expected to miss games against Tampa Bay, Washington, Vancouver, Buffalo, the New York Islanders, and Pittsburgh.

If Hextall's time line is correct, Mason would return Jan. 27 against visiting Arizona.

Hextall said Mason's injury was not chronic and that it "shouldn't affect him again."

As expected, the Flyers recalled goalie Rob Zepp from the AHL's Phantoms on Sunday. He figures to serve as Ray Emery's backup for most of the time Mason is sidelined.

On Monday, the Flyers host Tampa Bay, which sits atop the Eastern Conference and leads the NHL with an average of 3.23 goals per game.

Zepp, 33, is 11-5-4 with a 2.57 goals-against average and .921 save percentage with Lehigh Valley. On Dec. 21, he became the oldest goalie to win his NHL debut since 1926, registering a 4-3 overtime victory in Winnipeg in his only appearance with the Flyers.

"You never know how much of a setback this is until the guys replacing him play," Hextall said in a conference call with reporters. "Obviously, it's not what we want. It's a tough break for the hockey club, but it is what it is, and we're going to deal with it. In the end, Ray is a capable guy, and we brought Rob in for a reason - and this is the reason. Hopefully, it'll be a couple weeks and we get through the period without Mase."

Mason has been bothered by back and leg injuries recently. He collapsed to the ice on his back and left the game Saturday with 12 minutes, 53 seconds left in the first period and was replaced by Emery, who is 7-7-1 with a 3.21 goals-against average and .889 save percentage.

The Ontario native made a routine right-pad save on Craig Cunningham's long shot, then fell to the ice. He tried to push off on his right leg but was unable to do so.

Earlier in the week, Mason said he "tweaked" an injury - believed to be his right knee, which supposedly had a clean MRI exam on Wednesday - in a 3-2 overtime win over Washington on Thursday. He said he felt better at practice Friday.

Hextall said he had no regrets about playing Mason on Saturday because he was cleared by the medical staff - and there was no way to foresee a new injury.

Mason has a misleading 8-12-6 record with a 2.46 goals-against average and .920 save percentage.