PITTSBURGH—The Maple Leafs’ playoff hopes took a huge hit on Wednesday with word that Joffrey Lupul was out three-to-four weeks with a separated shoulder.

As well, Colby Armstrong is day-to-day with a broken nose. Both players were hurt in Tuesday’s loss to Boston.

“It comes at a bad time for us as we’re trying to make a playoff push,” said forward David Steckel. “We obviously can’t replace a guy like Joffrey Lupul. ... It’s an opportunity for some guys to get more ice time and perhaps showcase what they have to offer.”

Forward Carter Ashton was recalled on an emergency basis and made his NHL debut Wednesday night against the Penguins on a line with Tim Connolly and Joey Crabb.

Lupul hadn’t missed a game all year and was second on the team in scoring with 67 points, 25 goals and a team-leading 42 assists. Most of the assists came from playing on the top line with Phil Kessel.

“He’s been one of our cornerstones this year,” defenceman John-Michael Liles said of Lupul. “You look at how he and Phil played, how well they read off each other, how well they play with each other.”

Ashton was picked up at the trade deadline by GM Brian Burke at the cost of defence prospect Keith Aulie. He was picked 29th overall in the 2009 draft by the Tampa Bay Lightning.

His father, Brent, also played in the NHL. The 6-foot-3, 205-pound winger has 20 goals and 17 assists this season in the AHL, including a goal and an assist in three games with the Marlies.