The Flyers are giving Carter Hart his longest break from game action this season, hoping the extra work with goaltender coach Kim Dillabaugh will straighten him out.

But Hart, according to a league source, split up with his longtime sports psychologist and confidant, John Stevenson, before the season. And that might have as much to do with his struggles as his play on the ice. The split was because of something out of either person’s control, and not because of a conflict with each other, the source said.

Hart, 22, had been working with Stevenson since he was in grammar school in Alberta, and he has said being a goaltender is more about how you approach the game with your mind.

“I’d say about 90% of it is mental,” he said as he was working his way up the ranks. “Confidence is everything. Everything is between your ears.”

Hart has attributed a lot of his success to Stevenson, who has worked with numerous pro athletes, including Canucks goalie Braden Holtby, who won a Stanley Cup with Washington in 2018.

Stevenson was Hart’s goalie coach when he was 10. A year or two later, he became Hart’s sports psychologist, a person whose role is to optimize an athlete’s mental approach to their craft to improve performance.

“He’s helped me a ton,” Hart said in a 2018 interview, “and I wouldn’t be where I am without his help.”

Hart, who was not available to comment Monday, has said Stevenson helped him not only in hockey, “but life itself. ... He’s not only just my sports psychologist, but he’s a good friend of mine, so I can talk to him about pretty much anything, which is really nice to have. You can talk to your parents pretty much about anything, but there are some things you can’t tell your parents.”

Before the breakup, Hart said he tried to talk to Stevenson once a week during the season to fine-tune his mental approach to hockey.

Contacted in a text, Stevenson said he didn’t want to talk about the situation with Hart “out of respect for Carter.” He would not confirm or deny the split with his client.

In his first full NHL season last year, Hart was blossoming into one of the league’s best young goaltenders. He had a 2.42 goals-against average and .914 save percentage in the regular season, and was even better in the playoffs (2.23, .926).

This year, with a poor defense in front of him, he has a 4.04 GAA and an .869 save percentage. He has allowed four or more goals in 11 of his 20 starts and has been pulled in four of them.

Hart will not dress in the two games in Buffalo, and will do extra work with Dillabaugh, head coach Alain Vigneault said before Monday’s game against the Sabres. Brian Elliott started Monday and Alex Lyon was his backup.

» READ MORE: Alain Vigneault leaning on Flyers’ leaders to make sure they don’t take freefalling Sabres lightly

Vigneault said Elliott or Lyon would start Wednesday in Buffalo.

Hart will thus go at least three straight games without playing, his longest stretch of the season.

After Monday’s morning skate, Hart stayed on the ice and worked with Dillabaugh. He will do the same on Wednesday (another game day) and will have a practice with the team Tuesday. Hart will continue to work with Dillabaugh when the regular session ends.

“We’re going to stay that way for a little while here,” Vigneault said. “He needs to work on his game. He needs to work harder. He needs to work better. I had a good conversation with him and Kim about my expectations about his practice habits and him stopping the puck. Just like our team, everybody benefits from our good practices.”

Defenseman Shayne Gostisbehere said the team hasn’t lost faith in Hart.

“We all know Hartsy’s a good goalie.” Gostisbehere said. “Everyone goes through their ups and downs. Right now it’s a down, and then it’s the time of year where we need wins, so I think Hartsy’s going to be fine. It’s just he has to find himself and find his game. We know he’ll be back stronger. “

Gostisbehere added: “We’re definitely not worried about Hartsy at all. He’s definitely going to be hard on himself. That’s just the type of kid he is. ... I just know his personality and his attitude toward playing the game, and his preparation is second to none. I’m pretty sure no one in this organization is too worried about the Carter Hart we’re going to see next.”

» READ MORE: From the archives: If Flyers prospect Carter Hart has a long career, credit his sports psychologist

Breakaways

The Flyers went with the same lines and pairings Monday they used in Saturday’s 2-1 win over the Rangers. ... Vigneault on the Flyers’ being able to have a practice -- their first in 12 days -- before the Rangers game: “We were able to work on a couple things and I think it showed on the ice.”