"I had symptoms all last season and basically I can't skate as well as I can," Rathje said before the Flyers game Saturday night against the Rangers. "I can't shoot as well as I can, and it really drops my play down."
Rathje will have more tests Monday to decide if he needs surgery or rehabilitation. Flyers trainer Jim McCrossin said surgery would keep Rathje out about four weeks. If not, he could miss up to two weeks.
"Our goal is for Mike to have no symptoms when he comes back," McCrossin said.
Rathje had three goals and 21 assists in 79 games last season.