Maple Leafs-Sabres Preview
The Toronto Maple Leafs, meanwhile, want some goals out of Phil Kessel.
With Vanek's status unclear, the Sabres will try to end their skid and continue their home dominance over the Maple Leafs on Tuesday night.
Buffalo (2-3-0) beat Toronto (2-3-0) on the road 2-1 on Jan. 21, but has since dropped three straight.
The Sabres' slide continued with Sunday's 3-2 loss at Washington, as Vanek was sidelined by a strained muscle. The left wing had been on the ice for all 11 of his team's goals prior to that contest, scoring three and assisting on six - one versus the Maple Leafs.
Vanek has 16 goals and 13 assists in 24 career home meetings with Toronto, including 18 points during the Sabres' current 10-1-0 stretch at home against their Northeast Division rival.
While health is the concern for Vanek, a lack of production has been the problem for Kessel. He has gone without a point in his last four games, and is without a goal through five contests for the first time since he was a rookie with Boston in 2006-07.
The star right wing had seven goals in his first five games last season en route to 37 and 82 points - both career highs and team bests.
"He's had chances. You want your goal-scorer to feel good about himself, and in some games you see the frustration," coach Randy Carlyle said. "Our message is don't display those things, just go out and focus on the next one - how you can get one and focus on how you can help a teammate get one. Go to those dirty areas and stop in front of the net.
"Shoot the puck. Shoot the puck. He can shoot the puck as good as anybody in the league and that's what we want him to do."
Kessel came up empty on seven shots on goal against the Sabres last week and misfired eight times in his last visit to Buffalo, although he did have three assists in a 6-5 overtime loss April 3.
In that meeting, the Leafs blew an early three-goal lead, and they may be reminded of that after squandering two-goal advantages in their last two games. Toronto surrendered five goals in a row in a 7-4 home loss to the New York Islanders on Thursday before giving up five unanswered to fall 5-2 to the New York Rangers two days later.
"The two games were our worst two games of the year," Carlyle said.
Carlyle may be without Clarke MacArthur, who had the nail on his pinky come off when he was slashed Saturday. He has one goal and two assists in his last three games after setting up James van Riemsdyk's power-play tally at Madison Square Garden.
Defenseman Dion Phaneuf had a tough time in Manhattan, posting a minus-4 rating after putting up a minus-3 against the Islanders.
Jason Pominville is looking to get back on the scoresheet for Buffalo after being held without a point for the first time this season Sunday. He had two points against Toronto last week, and has posted 12 in the past 11 home matchups.
The Sabres must decide if 18-year-old Mikhail Grigorenko will remain with the team or go back to juniors. The 12th overall pick in last year's draft doesn't have a point through five games, and playing one more would use up a year of his entry-level contract.