Defenseman Matt Niskanen is the only regular in the Penguins lineup who’s not a sure bet to play in Game 1. Although head coach Dan Bylsma said last week that Niskanen would be ready for the playoffs, Niskanen is dealing with a shoulder injury that needs rest (from contact) according to a source and is one of those injuries that can easily reaggravate and cause a lot of discomfort. Although he doesn’t play a top-2 pairing role all the time, Niskanen has arguably been the Penguins No. 4 defenseman this season behind Kris Letang, Brooks Orpik and Zbynek Michalek. From a consistent standpoint, he’s been better than Michalek. With Niskanen not ready to get back on the ice, Brian Strait remains in the top-6 paired with Deryk Engelland.