Things could be even tougher for the slumping Lightning in Monday night's rematch, with Malkin expected to make his return from a concussion.
The reigning league MVP has missed four games since colliding with the boards in a 3-1 win over Florida on Feb. 22. The Penguins beat Tampa Bay 5-3 two days later but lost the next two before Saturday's wild 7-6 overtime victory in Montreal.
Brandon Sutter ended that game 52 seconds into the extra session and was one of three Pittsburgh players with two goals. Matt Cooke and Chris Kunitz were the others while Kris Letang had a career-high four assists and Sidney Crosby totaled three points.
The presence of Malkin should make that offense even more potent. He went through a full-contact practice Sunday and passed an imPACT test Monday, clearing him to return to game action.
"He was the same Geno," defenseman Deryk Engelland said of Sunday's practice. "It's good to see him out there and doing battle drills with him. He's a huge part of our team and our success, and to have a guy like that back is always good."
Malkin hasn't suffered from any headaches since his collision and experienced only short-term memory loss on the day he was hurt.
"In highlights, it looks bad," Malkin said. "But it's not that bad."
Pittsburgh (14-8-0) is thrilled to have him back for Monday's matchup considering he has eight goals and three assists in his last three games against Tampa Bay (9-11-1).
The Penguins have outscored the Lightning 23-9 in their four straight wins in the series.
Even with Malkin playing, the Penguins hope for another standout performance from Crosby, who had two goals and an assist in last month's win over Tampa Bay. The center has 17 of his 34 points over the last nine games.
Crosby has three goals and three assists in his last three against the Lightning, who haven't gotten much production lately from the league's highest-scoring offense.
The Lightning, averaging 3.48 goals to Pittsburgh's 3.45, have been outscored 14-7 during a four-game skid and couldn't take advantage of a pair of early goals Saturday in Boston. Steven Stamkos and Alex Killorn found the net in the first 8:38, but the Bruins rallied for a 3-2 victory.
"It's coming down to the same thing that's been going on for years and we're trying to break, that offense-first mentality," coach Guy Boucher said. "(We need to) keep hammering it, eventually the nail will go down deep enough. ... We have a lot of players that need to learn how to win."
The Lightning have given up 48 goals while going 3-10-1 since their stellar start.
Tampa Bay is 6 for 52 on the power play over the past 13 contests after converting 13 of its first 36 chances this season, but scored both goals Saturday on the man advantage.
"Our power play was better tonight," Stamkos said. "We generated some chances and we got two. Hopefully, we build on that."
Stamkos is riding a nine-game point streak, and his 32 points are two behind Crosby for the NHL lead. He had a goal and two assists in the loss to Pittsburgh after totaling two assists over the previous six matchups including postseason.