BOSTON — Brad Marchand is day-to-day with an upper-body injury after a collision with Florida Panthers forward Sam Bennett in Game 3 that the Boston Bruins said might have crossed the line.

The Bruins captain’s status for Game 4 on Sunday is uncertain. He didn’t practice with the team Saturday. Marchand is the Bruins’ leading scorer in the playoffs with 10 points in 10 games (3 goals, 7 assists).

The Panthers lead the series 2-1 after a 6-2 victory in Boston on Friday night.

Some on social media said a slow-motion replay shows Bennett making contact with Marchand’s head using his right glove as the Boston winger went for a check. Andrew Raycroft, a former NHL goaltender who covers the Bruins for NESN, called it “a sucker punch, not a reverse hit.”

A source told ESPN that the NHL department of player safety will not discipline Bennett for the play, which did not receive a penalty from on-ice officials.

Bruins coach Jim Montgomery didn’t see the incident in real time but said “having seen [the replay], there’s a history there with Bennett. He’s a good, hard player, but there’s clearly evidence of what went on. People can say it wasn’t intentional. We have our view of it.”

Montgomery said the history with Bennett isn’t with Marchand in particular but in delivering that kind of blow on previous hits.

In the Panthers’ series against the Toronto Maple Leafs last season, for example, Bennett’s right glove made contact with the face of forward Matthew Knies before Bennett slammed Knies to the ice. Knies was concussed on the play, and some said Bennett had delivered a sneaky punch to the Toronto rookie.

Florida coach Paul Maurice said he didn’t believe Bennett punched Marchand.

“No, and I don’t think most of you would’ve either,” he said Saturday. “It was just a collision. In a perfect world, every team has everybody healthy. Nobody likes to see him get hurt.”

Bennett returned to the Florida lineup for the first time since Game 2 of the first round against the Tampa Bay Lightning. He played 12:43 and assisted on Vladimir Tarasenko’s power-play goal that gave the Panthers a 2-0 lead.

“He hits hard. He’s thick and a really tough guy. He knows how to time it,” Panthers winger Carter Verhaeghe said. “It’s a huge skill how to time hits like that and get guys like that. There’s very few guys in the league like him that can do that and that have the skill set that he has.”

Marchand skated eight shifts in the first period and seven in the second period, amassing 10:51 in total ice time before departing. He didn’t register a shot on goal and had one shot attempt.

“You never want to see someone go down and not be able to come back, especially a guy who’s your leader and your best player. But that’s an opportunity for guys to step up, and we can do that,” said Boston center Charlie Coyle, who noted that the Maple Leafs rallied against the Bruins in the first round after losing star Auston Matthews to an upper-body injury.

“I think you’ll see guys take on more responsibility and rise to that occasion,” Coyle said. “We want to play for guys who are out of the lineup and we wish can be in there. We play for each other, and that’s something we’re going to do [Sunday].”