Sidney Crosby, the N.H.L.’s biggest star, said Monday that he was experiencing concussion symptoms again and that he would sit out indefinitely.

“After talking with everyone, I just figured it was better to be cautious here and not take any chances,” he told reporters in Pittsburgh. “That’s kind of where I’m at right now.”

Crosby, who missed more than 10 months after sustaining a concussion last January, said he was probably hurt when he was hit in the head while colliding with the Bruins’ David Krejci during a 3-1 loss Dec. 5. He said, “It didn’t feel like anything too major.”

He did not miss a shift, but later collided with his Penguins teammate Chris Kunitz near center ice. He sat out the next two games, against Philadelphia and the Islanders.