The Maple Leafs forward was disciplined for an illegal check to the head and interference against Lightning defenseman Erik Cernak during a 7-3 loss in Game 1 on Tuesday.
The incident occurred at 15:40 of the second period. Bunting was assessed a five-minute match penalty for an illegal check to the head. The Lightning scored two goals on the ensuing power play, by forward Corey Perry and center Brayden Point, to take a 6-2 lead.
Cernak left the game and did not return; Tampa Bay coach Jon Cooper said Wednesday the defenseman will not play in Game 2.
The Maple Leafs have lost in the first round in each of the past six seasons, including a seven-game loss to Tampa Bay last season despite holding a 3-2 series lead. Toronto has not won a series in the Stanley Cup Playoffs since 2004, and its last championship came in 1967.
With Bunting unavailable, Calle Jarnkrok replaced him at left wing on a line with center Auston Matthews and right wing Mitchell Marner at practice Wednesday.
Ryan O'Reilly was the center on a line with left wing Matthew Knies, who could make his Stanley Cup Playoffs debut in Game 2, and right wing Noel Acciari. John Tavares, who played left wing in Game 1 on a line with O'Reilly and right wing William Nylander, shifted to center between left wing Alex Kerfoot and Nylander.
The fourth line of center David Kampf between left wing Zach Aston-Reese and right wing Sam Lafferty remained the same.
"Our bottom-six (forwards) didn't have a great day yesterday, so there's that, but also I haven't made any lineup decisions in terms of how we will look tomorrow," Keefe said Wednesday. "I wanted to get John some reps back at center; he hasn't had those all week. If we end up moving things around, I want him to be comfortable there. But I haven't made any final decisions, so I wouldn't read too much into what we looked like today."
Knies, a second-round pick (No. 57) by the Maple Leafs in the 2021 NHL Draft, had one assist in three regular-season games after signing with Toronto following the conclusion of his sophomore season with the University of Minnesota.
"Tampa is a competitive team, the playoffs are a different animal, a lot more physical and a lot faster," Knies said about what he learned watching Game 1. "Special teams matter, staying disciplined matters and staying out of the box was a huge valuable lesson for this team.
"That would be awesome (to play in Game 2). It's every kid's dream to play in the playoffs and play for the Stanley Cup, so I would be super stoked and pumped to be a part of it."
O'Reilly said he has been very impressed with Knies, who had 42 points (21 goals, 21 assists) in 40 games with the University of Minnesota this season, since he joined the Maple Leafs on April 9.
"He's a great kid, works very hard, and you can see his skill set is unbelievable, the way he handles the puck and the plays he makes out there, it'll be exciting to play with him," O'Reilly said. "Hopefully we can generate a lot and be a line that is hard to play against but hopefully contribute offensively. I've been very impressed with him. You can tell he's going to have a long NHL career."
Keefe did confirm that Ilya Samsonov, who allowed six goals on 29 shots before being pulled at the end of the second period, would start for Toronto in Game 2. Joseph Woll stopped four of five shots in the third period Tuesday.
NHL.com independent correspondent Dave McCarthy contributed to this report
