What’s happening in the Bruins’ coaching search?

Known commodities, meanwhile, have filled vacancies in Dallas (Peter DeBoer), Florida (Paul Maurice), and Philadelphia (John Tortorella). Winnipeg has long been linked to the most experienced coach on the market: Barry Trotz, whose win total (914) ranks third all-time. Vegas, whose roster has zero players under 23, turned to Cassidy to get the most out of its win-now group.

The next coach of the Bruins may be able to lean on Patrice Bergeron — the captain has not said whether he will return for a 19th season — but on the whole, the Bruins are trending young.

With Brad Marchand (double hip surgery), Charlie McAvoy (shoulder), and Matt Grzelcyk (shoulder) out at the start of next season, inexperienced players will likely see opportunity. Beyond that, the new hire must maximize the prime years of David Pastrnak, 26, and McAvoy, 24.

Sacco and Leach have worked with current Bruins players, as has Carbery (albeit more briefly). Quinn also has fans in the dressing room.

Before his three-year stint on Broadway (96-87-25), Quinn spent 2013-18 coaching Boston University. After taking over for Jack Parker, Quinn, a former BU defenseman, went 105-68-21, with a national championship game appearance in 2015. Among his charges were McAvoy (for two seasons) and Grzelcyk (three).

“Quinny was awesome to play for. I’ve said it like 100 times,” McAvoy said last January, as Quinn prepared to coach Team USA in the Beijing Olympics. “We related on a very high level.”

Quinn, drafted 13th overall by the Minnesota North Stars in 1984, was considered a top prospect. The Cranston, RI, product spent three years at BU and shined internationally, including at the 1986 World Junior Championships. However, the discovery of a rare blood disorder (Christmas disease) knocked him off an NHL track. He played in 79 pro games, with AHL Binghamton and IHL Cleveland.

“With his past, I just kind of saw myself in that, and I saw a guy with a lot of experience,” said McAvoy, a Team USA star who signed on to play under Quinn and was drafted 14th overall after his freshman season. “I think he does such a good job of being so inviting and opening up to all the recruits and the kids. There’s something about him that you just really gravitate toward, his personality, his coaching ability.

“Just everything I know about Quinny — his personality, his charm — when he says, ‘Jump,’ I would say, ‘How high?’ ”

Grzelcyk, drafted in 2012 (third round, 85th overall) when Quinn was Parker’s assistant, logged two seasons (2014-16) as a captain. He said Quinn took a genuine interest in every player’s life, and is “someone I’m very close with still.”

Quinn, who replaced Alain Vigneault as Rangers coach after the 2017-18 season, was hired by president Glen Sather and GM Jeff Gorton to oversee a rebuild that began in February of 2018 when Sather and Gorton detailed their plans in an open letter. Quinn was fired after three non-playoff seasons, as was Gorton, now Montreal’s vice president of hockey operations.

Quinn would have to answer for why the Rangers fell flat at the end of his tenure. Sacco would have to prove he still has the chops to be an NHL head coach.

Sacco, who joined Claude Julien’s staff in July 2014, was retained by Cassidy after the Bruins fired Julien in February of 2017. A forward by trade (13 NHL seasons, most notably with the expansion Mighty Ducks), Sacco ran the Bruins’ penalty kill . The unit ranked ninth, second, and third in the NHL the last three seasons.

Joe Sacco (right) has been a Bruins assistant coach under both Bruce Cassidy (left) and Claude Julien.Matthew J Lee/Globe staff

After Sacco was a Jack Adams Award finalist in 2009, his Colorado teams missed the playoffs three years in a row. His record — 130-134-30 — was underwhelming.

The only Bruins candidate who has similar knowledge of the current roster is Leach. The former Bruins farmhand rode buses with Bergeron in the lockout year of 2004-05. As Providence’s coach (2016-21), he sent several players to the varsity, including Grzelcyk and Jake DeBrusk.

“He’s got the EI — emotional intelligence,” said an NHL agent who has known Leach since his playing days. “He’s really good at talking to players, communicating, understanding their journey.”

An opportunity was not available on Cassidy’s staff, so Leach ran the penalty kill and defense for Dave Hakstol with expansion Seattle last year. The Kraken ranked 30th on the PK and 24th in goals against.

Other current Bruins who played under Leach include Jack Studnicka, Trent Frederic, Jakub Zboril, and Connor Clifton — all of whom also worked with Carbery during his year as a Providence assistant (2017-18).

Last season, Carbery ran the Maple Leafs’ best-in-class power play (27.3 percent), which ranked 16th before his arrival.

Carbery, at 40 the youngest candidate on the list, was AHL Hershey’s head coach from 2018-21.

As a speaker during a December 2020 clinic for the NHL Coaches Association, Carbery extolled the virtues of being adaptable.

“You’re going to have some core fundamental things that you believe as a coach and you want to do,” Carbery said. “But I would definitely challenge you to be flexible and be able to identify that maybe we’re a different makeup than what you might want your group to be.

“You have to be open to reading your players and what type of team you have, and adjusting your identity a little bit off of that.”

Montgomery went 125-57-26 at the University of Denver (2013-18), with two Frozen Fours and a national title (2017).

The Maine alum reached the second round with the Stars in 2018-19, but his promising tenure was aborted in December of 2019. Dallas GM Jim Nill fired him for a “material act of unprofessionalism,” later revealed to be related to Montgomery’s alcoholism.

The deposed coach sought treatment, then resurfaced as a St. Louis assistant in September 2020. His penalty kill ranked fifth last season (25th in his first year).

Like the rest of the Bruins’ anticipated candidates, he is considered to be player-friendly.

Andrew Mahoney of the Globe staff contributed to this report.


Matt Porter can be reached at matthew.porter@globe.com. Follow him on Twitter: @Matttyports.