The injury news just keeps getting worse for the Pittsburgh Penguins.

Evgeni Malkin — who had just returned from a five-game absence — has a major knee injury, coach Dan Bylsma said Saturday. And from the looks of it, the star forward won't be back anytime soon.

Sidney Crosby is already out with a concussion, and his return date is unknown. Mark Letestu has a meniscus injury. He's out four to six weeks.

According to Bylsma, Malkin, the All-Star center who has 15 goals and 22 assists this season, has two torn ligaments in his right knee. It's not clear if he'll need surgery.

Malkin was injured during Friday night's 3-2 home win over Buffalo. He had an MRI on Saturday, which showed the tears to both the anterior cruciate and medial collateral ligaments. Bylsma said treatment options are being discussed.

"You're talking about Evgeni Malkin and the quality of player that he is. He's a guy that's won a scoring title and a Conn Smythe (trophy)," Bylsma said. "We were anticipating getting him back in the lineup and healthy back in the lineup. This is a difficult injury for him."

Malkin nursed a knee problem as well as a sinus infection during his recent absence, which included him skipping All-Star weekend in Raleigh, N.C. But he practiced with the team this week, and managed three shots against the Sabres. However, he had just 6:03 of playing time, before colliding with Buffalo defenseman Tyler Myers in the second period.

"It was kind of a fluke situation going into the boards with a guy," Bylsma said. "That's a tough injury for Geno. We have dealt with games without him. We've managed to find our way without him. That's what we're going to have to look at now."

So, the Penguins indeed will journey on without their top two stars. Crosby is not even with the team this weekend, as he's back in Canada, visiting his parents. He has missed 12 games.

Through it all, though, Pittsburgh continues to win games and maintain its place in the Atlantic Division. The Penguins have won five in a row, including all three since the All-Star break. With 72 points, they were just one point behind first-place Philadelphia as play began on Saturday.

That said, clearly, the Penguins were building momentum as they prepared to be at full strength. Now, that appears unlikely.

"It really was the second part of the contact that made the hit. That was two guys kind of going into the boards on their own that happened to land on each other, which caused the hit," Bylsma said. "I don't think at the point of injury, that (Tyler) Myers had any intent of even making contact with anybody."

Malkin is in his fifth year in the NHL, and has had at least 70 points in his first four. He has two 100-point seasons, and scored a career-high 47 goals in 2007-08.

Pittsburgh meets Washington on Sunday.