Jim Montgomery had tried a lot of different line combinations and changes through the first 10 games, but there was one grouping with which he had not tinkered.

That is about to change.

Center Elias Lindholm had been signed to a seven-year, $54.25 million contract primarily to be strong two-way center while also feeding David Pastrnak, one of the top goal-scorers in the NHL. The theory was sound. So far, however, it has not worked. The last straw was Tuesday’s 2-0 loss to a previously porous Flyers team.

In Wednesday’s practice at Warrior Ice Arena, the Bruins’ coach completely overhauled his forward lines, breaking up the Lindholm-Pastrnak connection while also sprinkling the members of the fourth line – the only effective forward combo – throughout the lineup.

Montgomery had Pavel Zacha centering Pastrnak and John Beecher, Lindholm between Brad Marchand and Mark Kastelic, Matt Poitras centering Trent Frederic and Justin Brazeau, and Charlie Coyle at center with Max Jones and Cole Koepke. Tyler Johnson, still waiting to be signed, took a turn on the Lindholm-Marchand line.

As far as personnel shifts, there aren’t many major moves for Montgomery to make. He was at a loss to explain why the Lindholm-Pastrnak combo has not worked.

“It should work,” said Montgomery. “Two smart hockey players, two players that see the ice really well, two players that can shoot and pass, two players that can skate. It just hasn’t materialized, so we’re changing it up.”

It was understandable that Montgomery tried to let the combo marinate for a bit, but the change had to be made. Lindholm and Pastrnak combined for just one 5-on-5 goal, which came in the second game of the season against Montreal. Lindholm is without a point in the last seven games.

Lindholm had missed the first week of training camp with an injury, which probably didn’t help, but he had actually gotten off to a decent start, posting 2-3-5 totals in the first three games. He’s posted zeroes across the board since then.

“I think we’re just a little out of sync,” said Lindholm of his connection with Pastrnak. “Obviously for myself, I haven’t been playing the way I want to and I think that affects both of us. And I think he obviously wants to play a little bit better as well. When you’re at this level in this league, it’s a really good league, so it’s hard to connect.”

Lindholm was robbed by Sam Ersson on a chance in the B’s 2-0 loss to the Flyers on Tuesday and he also had a nifty tip that was turned away.

“If the chances are coming like they did (Tuesday) then I’ll be fine, but it’s not good enough,” said Lindholm.

Marchand and Lindholm have played together only sparingly in some penalty kill and 4-on-4 situations.

“He’s obviously a good player. He’s been around for a long time and those times I’ve played with him, he’s easy to play with and he works hard at winning pucks and he has a good shot. Hopefully we can do something good,” said Lindholm.

While Zacha had been the left wing on the Lindholm-Pastrnak line, moving him to the middle gives Pastrnak some familiarity. Zacha centered him last year and the combo was pretty successful in the regular season, helping the right wing to a 47-63-110 season while Zacha had a career-high 59 points (21 goals, tied for a career best).

Zacha faltered in the playoffs and was moved to the wing, but the B’s have to get to the post-season first. That is hardly a sure thing right now.

The break-up of the fourth line was also significant.

“The message to those three (Kastelic, Beecher and Koepke), and that was the most important message, was ‘you guys are being split up to help the other guys be better, not for you to become ‘skill players,’” said Montgomery. “I don’t want their games to change. I want them to play north, I want their work habits to rub off on other people to create more turnovers, create more opportunities.”

Any line combos, however, will only work if the handful of top forwards get past the yips that they seem to have when handling the puck. Passes are rarely on the tape and, and when they are, they’re fumbled by the receiver. Players are even failing to do the simple task of getting pucks deep for a line change. On Tuesday, that snowballed after a failed 5-on-3 in the first period.

“Guys aren’t comfortable right now feeling the puck. The old adage of squeezing it tight. And it’s mental,” said Montgomery. “I was surprised by (Tuesday) night, that we were tight, that we weren’t executing. Because we had a good game, we had a lot of offense against Toronto and came out with a real good win. And I thought we had a lot of O-zone time in the first two periods. But we’re not executing offensive opportunities that are there. Our checking was pretty good for the most part. Most of their offense came off puck decisions when we had it on our tape … and those are the things where guys aren’t playing on instinct, they’re thinking. Any sport, if you’re thinking instead of just being in the moment, you’re not going to play fast. It’s obvious where the puck is going. That’s why a lot of pucks are getting picked off.”

Toward the end of Wednesday’s practice, Frederic and defenseman Parker Wotherspoon got into a brief shoving match at the end of a drill. It was quickly broken up and could be barely be called a dust-up. But it was perhaps indicative of the rising tensions on this team. The Bruins are 4-5-1 and, more importantly, playing quite poorly every other game.

Next up is Carolina in Raleigh on Thursday against the 6-2 Hurricanes. A win is a not a must just yet. But Montgomery needs to see some better execution. He’s running out of options.