The Penguins will be without defenseman Matt Niskanen for two-to-four weeks because of an ankle injury he suffered Sunday in Ottawa.

Niskanen was wearing a walking boot Monday. The injury is not considered season-ending.

Simon Despres filled in for Niskanen against the Islanders and played alongside defenseman Kris Letang. Despres and Letang skated together during much of the team's abbreviated training camp.

Letang has taken Despres under his wing.

"I try to help him as much as I can," Letang said. "Everyone knows that, for defensemen, it's a different game when you get here.

"You can't really rely on your speed or your skill. You have to be smarter than the opponent. Teaching him a few things is important. I take pride in that."