Lehner, 24, was the Senators' second pick (No. 46) in the 2009 draft. He played 86 games for the Senators between 2010 and 2015, and was 30-36-13 with a .914 save percentage and 2.88 goals against average for Ottawa.
Lehner became the odd man out in the Senators crease with the emergence of Andrew Hammond last season behind No. 1 goaltender Craig Anderson.
Lehner sprained his ankle in his Sabres debut against the Senators Oct. 8 and missed 39 games.
This will be the fourth game of his return; he has lost his previous three starts. Lehner has a .936 save percentage and 2.36 goals against average since his return.
Chad Johnson played Monday in the Sabres' 6-3 loss to the New York Rangers, their third loss in a row.
"I think there will be some energy to the game," Senators wind Mike Hoffman said. "I'm pretty sure [Lehner]'s looking forward to getting his first game back here. At the end of the day, it's another team in the League we have to be ready for. We can't take shifts off. Teams are too good."
Inconsistency has been an issue for the Senators this season, the proof of which has been their inability to string wings together.
They are coming off one of their best efforts of the season, a 3-0 win against the Rangers at Canadian Tire Centre on Sunday.
"I think we were just determined," Hoffman said. "Everyone was right in from the drop of the puck until the end of the third period, starting with the defense to the forwards, and our goalies have been outstanding this year. If we play that way every night, there's no reason why we shouldn't come away with more points than not."
Said Senators defenseman Mark Borowiecki: "A big win doesn't really mean much if you can't string some together. For us, we want to go into this [All-Star] break feeling good about ourselves and carry that confidence through into the next game."
Here are the projected lineups:
SABRES
Evander Kane - Ryan O'Reilly - Jamie McGinn
Matt Moulson - Jack Eichel - Zemgus Girgensons
Marcus Foligno - Johan Larsson - Brian Gionta
Cal O'Reilly - Tim Schaller - David Legwand
Zach Bogosian - Rasmus Ristolainen
Jake McCabe - Cody Franson
Mike Weber - Mark Pysyk
Robin Lehner
Chad Johnson
Scratched: Carlo Colaiacovo, Phil Varone.
Injured: Cody McCormick (blood clots), Tyler Ennis (upper body), Nicolas Deslauriers (lower body), Sam Reinhart (upper body), Josh Gorges (undisclosed).
SENATORS
Mike Hoffman - Mika Zibanejad - Bobby Ryan
Matt Pumpel - Jean-Gabriel Pageau - Mark Stone
Curtis Lazar - Zack Smith - Alex Chiasson
Shane Prince - Max McCormick - Chris Neil
Mark Borowiecki - Erik Karlsson
Patrick Wiercioch - Cody Ceci
Jared Cowen - Chris Wideman
Craig Anderson
Andrew Hammond
Scratched: None.
Injured: Kyle Turris (lower body), Marc Methot (lower body), Chris Phillips (back), Clarke MacArthur (concussion), Milan Michalek (broken finger).
Status report: Senators defenseman Marc Methot, who has missed the past four games with an injury, will be a game-time decision, Senators coach Dave Cameron said. Senators top center Kyle Turris will miss his fourth game with a lower body injury.
Who's hot: Zibanejad has two goals and four assists in his past five games … Ryan has four goals and two assists in his past five games.
