from Fran Seravalli of the Philadelphia Daily News,

According to general manager Ron Hextall, Mason is ruled out for at least this weekend's games in Toronto and Winnipeg with an "upper-body" injury, but the team would not commit to any timeline after that.

That doesn't necessarily mean Mason will miss only this weekend. Hextall said the team will provide an update on Monday and would not comment further.

The scene yesterday was ominous. With the help of the training staff, Mason was flipped over to his back - where he stayed for a period of time - before sitting up and finally making it to his feet. He was then helped off the ice, unable to skate off under his own power....

R.J. Umberger said Mason's injury "looked like" a back issue, noting Mason "grabbed something behind him" when he "reached for a puck" to make a save.

Luke Schenn saw Mason go down and had his own theory.

"It looked like he was going into a spasm or whatever it was," Schenn said. "I'm not even sure. You never know if it's dehydration or anything like that.

more

update 12:06pm, via Tim Panaccio of CSNPhilly,

“He sees the specialist on Monday and we’ll find out more,” Hextall said. “I talked to him and the doctor does not have a hands-on [feeling] for Mase yet. He’s talked to [trainer] Jimmy [McCrossin].

“I’m optimistic is won’t be long. Until you get the information you don’t know for sure. I don’t anticipate it being a long time but it could change.”