Exclusive: 4 players on firm ground, tough competition heats bruins.

At the moment, the Bruins’ top four defensemen appear to be on firm ground. But the third pairing? Well, that appears to be a question that still needs answering, and there could be some experimenting in the final 13 games before the playoffs.

In Monday’s practice, Charlie McAvoy took his usual spot with Matt Grzelcyk while  Hampus Lindholm was paired with Brandon Carlo in the usual second unit.

But with four players to fill two spots, the coaching staff went with two lefties (Mason Lohrei and Parker Wotherspoon) for one pairing and two right-handed D-men (Kevin Shattenkirk and Andrew Peeke) for the other.

“You’re trying to see if guys are comfortable playing the offside, especially when we knew today was going to be a good practice where we would be defending the rush a lot,” said Coach Jim Montgomery after Monday’s practice in Brighton. “There were three drills defending the rush, so we see guys playing on the offside. And we tell them to switch, so they get comfortable playing with each other like that. And then a little bit is just seeing what we have.”

Shattenkirk, a scratch the last two games, played on the left side in practice with Peeke, something he’s done sparingly during his lengthy career. While there was no confirmation that he will play on Tuesday against the Ottawa Senators, he was on the second power-play unit, which is usually a pretty good clue.

A veteran of 15 NHL seasons and a pro’s pro, Shattenkirk expected to be in a battle for playing time.

“That’s part of being on a good team,” said Shattenkirk. “There’s going to be competition for third line, fourth line, third pair roles. I think I expected them to be feeling things out and trying to see what the lineup’s going to look like in the playoffs. You can’t really dwell on it too much. I’m happy with where my game has been in the last six or seven games. I think it’s more of just making sure you’re staying in that groove and not lose confidence in what you’re doing. I think it helps, too, when you have good communication from the coach, which I have. It’s not like I’m being completely left in the dark about (being out of the lineup).”

For a right-handed shot, playing on the left side presents some challenges, though it could also benefit an offensive-minded player like Shattenkirk.

“For sure, it’s different. You just have to maybe think about your play a little bit more,” he said. “I think the hardest part is when you’re getting D-to-D passes, whether it’s in the D-zone or the neutral zone, it’s hard to get your head around and find that strong side option a lot. So that’s just something I try to remind myself of. But it frees you up in different ways on the offensive blue line, when you get D-to-D passes having the ability to take a one-timer or get to the middle quicker off the wall. There are definitely pros and cons.”

“I think he’s as advertised,” said Shattenkirk of Peeke. “He’s a big defenseman, plays physical. Last game, that assist he had was what we preach on the blue line, getting involved as defensemen. As I know, it’s a different system to get used to. I’m not sure what they were doing in Columbus but I think we’ll all try to help him out and make it as seamless as possible for him to get in and get adjustment.”

Whether Lohrei is deemed to be ready for playoff action remains to be seen. He saw first-pair duty in Montreal last Thursday when Grzelcyk was sick, then was scratched. The rookie’s got some of the best stick skills among the eight defensemen, but he has also had challenges in the defensive zone from time to time. And once the playoffs start, every mistake is magnified. At this time of year, development takes a backseat to winning.

“To me, this time of year there are no more rookies. You’re a first-year player now,” said Montgomery. “Our approach with him is he may see more video for his development, he may see more on-ice instruction from our skills coach and assistant coach John McLean. But as far as my approach with the players? Everything’s the same. You earn what you get. If you play well, you’re going to keep playing. If you have a hiccup in a game, you’re going to watch for a bit and then you go and apply it the next time you get in. It’s not about development right now.”

At some point, the coaching staff will zero in on a top six. But things can change quickly in the playoffs and history shows that eight defenseman can be the bare minimum needed to get through a long playoff run.

“Obviously, when we get closer to playoffs or in playoffs and when things are working and the team’s winning, I know that you’re not going to expect to get back in at that point,” said Shattenkirk. “But you have to stay ready if you’re out of the lineup. And if you’re in the lineup, you do your job and play your role. Again, if you look at the group that we have, there could be, based on our matchups, different guys playing against different teams. That’s on us and making sure we’re staying ready and staying focused as well, so that when we come in, we’re able to get right back up to game speed.”

• Montgomery had no update on Pat Maroon, who underwent back surgery on Feb. 7, other than to reiterate he remains week-to-week and he will not be available this week.

• The Providence Bruins signed Notre Dame goalie Ryan Bischel, the 2023 Big Ten Goaltender of the Year for 2023, to a one-year AHL contract for the 2024-25 season. In 105 NCAA games, Bischel posted a 2.46 goals against average and a .924 save percentage.