Ahead of schedule, Charlie McAvoy returned to the lineup for the Bruins

McAvoy smiles as he watches a replay of his second-period goal Thursday night at TD Garden.John Tlumacki/Globe Staff

The Bruins, humming along with the best record in the NHL’s Eastern Conference (11-2-0), got better Thursday.

Their No. 1 horse on defense, Charlie McAvoy, suited up against the Flames.

“Your observations yesterday were accurate,” coach Jim Montgomery said before an optional morning skate in Brighton. “He’s checked all the boxes.”

McAvoy’s return comes approximately three weeks before his targeted date of return from left shoulder surgery. He had an arthroscopic stabilization procedure June 3 and was expected to miss six months. Like teammate Brad Marchand, who returned a month early, McAvoy cleared his hurdles quickly.

“Nice to have another Charlie,” Charlie Coyle said. “Tough being the only one for this long. We have a lot of guys who can chip in and play, but it’s always nice when you have a healthy roster and have everyone going.”

McAvoy was slated to open the night paired with fellow Boston University product Matt Grzelcyk. The other defense pairs were Hampus Lindholm with Connor Clifton, and Jakub Zboril with Brandon Carlo.

“We’re very fortunate with the D corps that we have,” Montgomery said. “We don’t need him to play 24 minutes, but I expect him to play 20 tonight.”

Any coach would be salivating at adding a Norris Trophy-caliber defender. Montgomery was no different.

“Just how he impacts the game in all three zones,” said the coach. “It doesn’t seem like he takes a second off, whether he’s pressuring pucks, he’s ending plays, he’s hitting someone, or he’s taking the puck from the breakout through the neutral zone, kicking it out, and driving the net, or getting a chance at the net.”

Centers among the tops

The Bruins entered Thursday with three centers in the top 25 for faceoff percentage: Patrice Bergeron (fifth, 61.3 percent), Tomas Nosek (15th, 58.1 percent), and Coyle (25th, 55.6 percent). David Krejci was no slouch, at 53.5 percent.

Bergeron and McAvoy celebrate at the end of Thursday's win.John Tlumacki/Globe Staff

Coyle’s improvement is significant. He has been underwater on faceoffs nearly his entire career, winning less than 50 percent in nine of his 10 previous seasons. His rate this year is a career high, and is much better than what he showed in his first two full seasons in Boston (49.1 last year, 48.3 the year before).

He has won the trust of Montgomery, who already liked to use Coyle in close-out situations because of his elite puck-protection skills. The faceoff improvement means that Bergeron and Krejci aren’t the only trusted righties in crucial situations.

Coyle said his improved health and strength this year has allowed him to dig in more. He doesn’t have Bergeron’s reservoir of knowledge about opposing centermen, but he’s one of the strongest players on the team.

“That’s something he’s taken on himself,” Montgomery said. “He’s done a really good job this year.”

On Monday against St. Louis, Montgomery asked Coyle to stop Ryan O’Reilly, long known as one of the best in the league at the dot (career win percentage: 55.8). Coyle won seven of eight draws against the Blues captain, and 10 of 14 (71 percent) overall.

Reilly clears waivers; Forbort on IR

Veteran defenseman Mike Reilly cleared waivers and was sent to Providence. “It’s not easy,” Montgomery said. “It’s the unfortunate part of the business. You get to know people, and they are people, and you care about them. We’re only allowed to carry 23 men.” … In addition to demoting Reilly, the Bruins placed Derek Forbort’s $3 million salary cap hit on long-term injured reserve to clear space for McAvoy … Linus Ullmark started his sixth game in a row. He entered having allowed more than two goals in just three of his 11 appearances, and more than three goals just one time ... Bruins looking for their first goals of the year included Nosek (whose drought entered its 72nd game), Carlo, and Zboril ... A.J. Greer sat for a second consecutive game. Craig Smith rode the fourth line with Nick Foligno and Nosek, while Trent Frederic was promoted to Coyle and Pavel Zacha’s line … McAvoy (1-0—1) landed two shots, five hits and blocked two shots in 19:18 … David Pastrnak (1-1–2) put a game-high 8 of his 12 attempts on goal. He is third in NHL scoring (9-13–22) … The Bruins were scorching at the dot (68 percent), with Bergeron winning 15 of 19 draws (79 percent) … The Bruins had more shots on the power play (15) than they did at even strength (13).

Montgomery facing old coach

Montgomery was facing his old coach, Calgary’s Darryl Sutter. Montgomery spent part of the 2000-01 season with Sutter’s San Jose Sharks. “I’m not as good behind the mike, or as funny,” Montgomery said, referring to Sutter’s blunt, bone-dry press conferences, “but I learned a lot from him. You learn how to hold people accountable at a high level, and really communicate to people what their role is.” … Montgomery’s predecessor, Bruce Cassidy, also played for Sutter during the early years of Sutter’s time in the Chicago organization (1987-95) … Calgary center Kevin Rooney, of Canton, had 50 postgame passes set aside for family and friends. He grew up a Milan Lucic fan, and now he skates with him on the Flames’ fourth line. “When you’re a kid, you’re just expecting Super Bowls and World Series,” said Rooney, 29, referring to the Boston sports scene. “When you talk to the older people, you realize this didn’t come around very often when they were growing up.”