SUNRISE, Fla. — It was not a good night for a number of Bruins, including David Pastrnak, who saw his ice time cut and his line switched.

Though he scored at 7:00 of the first — a goal the Panthers challenged as an offside and lost — Pastrnak ended Monday’s 5-4 overtime win on the fourth line, swapped with Brett Connolly. Pastrnak played just three shifts in the second period and three more in the third, though he did get a shift in overtime.

It was another night of development for a player who is still just 19 years old.

“Pastrnak was turning pucks over,’’ coach Claude Julien said when asked about the swap. “He wasn’t strong on the puck. When you play against top lines, it becomes dangerous. So I had to make a decision. It’s what it is and you move guys around.

“He didn’t necessarily sit the pine, but I couldn’t play him against top lines. It was as simple as that. He’s got to get back to what he was doing well before. That’s being heavier and making stronger plays. A lot of times he’s forcing plays, pucks are turned over, we end up in trouble. That’s part of a young player having to learn the game in those situations.’’

Connolly, who also scored on Monday, was moved up to play alongside Loui Eriksson and David Krejci, with Pastrnak dropped down to play with Landon Ferraro and Noel Acciari. Pastrnak finished with 9:33 of ice time and three shots on net.

Trotman back in

The good news was that Kevan Miller’s injury did not appear to be as bad as it was when he was hit by Alex Ovechkin on Saturday night, sending the Bruins defenseman skating off the ice holding his right shoulder.

The bad news was that he wasn’t on the team’s trip to Florida for a key two-game swing.

Without Miller — the team labeled him “day-to-day’’ with an upper-body injury — the team slotted Zach Trotman back into the lineup. Trotman, who was paired with Torey Krug to start Monday’s game, had been in the press box for the last eight games.

“You see a lot of stuff sitting up top,’’ Trotman said. “It looks like a pretty easy game when you’re sitting up there. I try and watch things and watch reads and stuff like that, but I try not to nitpick and say, ‘Oh, I need to do that or this more,’ because it’s too easy to sit up there and read everything.

“The biggest thing is just the intensity level’s got to stay up, the physicality, and be ready to play.’’

Trotman ended up logging 10:12 of ice time Monday. He dished out two hits and had a plus-1 rating.

Trotman has had several lengthy stays out of the lineup this season, going 11 games at the start of the year after a rough opening night, and sitting 10 of 11 games in a stretch in December.

So he has done this before.

He has also been part of a playoff push. Last season, he played the final 10 games of the regular season under dire circumstances. The Bruins did not make the playoffs.

“The closer it gets to playoffs, the more intense everything gets,’’ Trotman said. “You have to be prepared all the time. Just work hard and be ready for when the team needs you.’’

And, at least at the moment, the team needs him now.

“I don’t have to wonder what it’s going to be like, I know what it’s going to be like,’’ Trotman said of the final month. “I know what to expect, so it takes a little bit of anxiety out of it, wondering what’s going to happen out there. I know what to expect and I know how you have to play and the intensity level you have to bring every night.’’

So his focus, upon returning to the lineup, is simple, he said: “Moving my feet. It just leads to me playing better all around. That’s going to be my thing, moving my feet and playing with some composure.’’

A hit in Florida

Shawn Thornton had contemplated retirement, but only because he wasn’t sure that a team would be willing to offer him a contract for another season, one in which he will be 39 years old. But the Panthers opted to give him an extension two weeks ago, keeping him in Florida for another season.

“It was a pretty good decision coming down here, the way the team’s playing, obviously being able to play for another year,’’ Thornton said. “Not sure if that would have happened many other places.’’

“The only hesitancy was whether somebody wanted to pay me for another year. I said I’d play until they ripped the skates off me, so looks like it’s going to be another year. Obviously that’s probably going to be it for me and who knows how much I’m going to be in the lineup.

“I think it’s more being around the room and doing the same things that some of the older guys have been doing around here – holding people accountable and helping teammates out with any issues, trying to be a good voice in the locker room.’’

Thornton played for the Bruins for seven seasons, winning a Stanley Cup, before moving to Florida in 2014. This season, he has been in the lineup for 40 of the Panthers’ 67 games.

He has one goal and two assists and 71 penalty minutes — 19 of those coming Monday. In the second period, he instigated an uneventful bout with Adam McQuaid. In the third period, he was whistled for interfering with Krejci.

Night of milestones

The Bruins certainly didn’t make win No. 388 easy on Julien. The overtime victory — in which the Bruins blew leads of 3-0 and 4-1 — pushed Julien past Art Ross as the winningest coach in franchise history.

Julien has a record of 388-216-85, plus a Stanley Cup title, since he was hired in June 2007.

The Bruins will honor Julien with a ceremony prior to a home game with the Panthers on March 24.

A former player of Julien’s, the Panthers’ Jaromir Jagr, hit a milestone, too. He passed Gordie Howe for third on the all-time points list with 1,851.

Father’s day

Zdeno Chara did not fly with the Bruins on Sunday, instead joining them mid-day Monday after the birth of twin sons Ben and Zack. He led the Bruins with 25:18 of ice time and assured the media that he got some sleep Sunday night. “It’s obviously an amazing thing,’’ Chara said. “I give a lot of credit, obviously, to my wife. Very grateful and blessed. It was an unbelievable experience and we welcomed two sons to our family. Very happy about that. Now it’s kind of waiting till they’ll be able to come back home and we could be all together as a family.’’ . . . Zac Rinaldo was suspended five games in the AHL for his check to the head Friday in his first AHL game after being sent through waivers by the Bruins. He is also currently suspended for five games in the NHL for a hit on Cedric Paquette, a punishment that he will serve the next time he is in the NHL.

Amalie Benjamin can be reached at abenjamin@globe.com. Follow her on Twitter @amaliebenjamin.