Center Patrice Bergeron anchors the top line for the Boston Bruins. The center position should be a strength for the team in the 2019-20 season. Winslow Townson/Associated Press

BOSTON — Maybe we had Bruce Cassidy all wrong.

Over two-plus seasons as head coach of the Bruins, Cassidy has acquired a reputation as a tinkerer – not necessarily a guy to make changes simply to make changes, but someone forever curious to see how a switch or a swap might work out.

As the 2019-20 season dawns, however, the list of areas Cassidy doesn’t want to mess with is long. There’s been no talk of taking David Pastrnak off Patrice Bergeron’s line. The top two defense pairs (Zdeno Chara-Charlie McAvoy; Torey Krug-Brandon Carlo) will stay as is. Goalies Tuukka Rask and Jaroslav Halak will be more tandem than starter-backup combination.

And Cassidy doesn’t want to disturb what he calls a four-headed monster down the middle of the ice. In Bergeron, David Krejci, Charlie Coyle and Sean Kuraly, the Bruins have a group of centers that may rival the Bergeron-Krejci-Chris Kelly-Gregory Campbell depth chart that helped make them one of the NHL’s best teams from 2010-11 through 2014-15.

“I think it might be a little too early to talk about that,” Krejci said, “but obviously, there is that potential. And you do need that in this league – strong center icemen on all four lines.”

The fact that the Bruins haven’t had Coyle for a full season is one reason why comparisons may be premature, but he is the primary reason Cassidy thinks he can take arguably the NHL’s deepest group of centers into the season.

Much like the acquisition of Kelly from the Senators in 2010-11, Coyle was acquired from the Wild (for Ryan Donato) just before last season’s trade deadline, needed time to adjust (he was only 2-4—6 in 21 regular-season games), then became a force in the postseason. Coyle tied for the team lead with nine goals over 24 playoff games, and among centers, he tied Krejci for second with 16 points – one behind Bergeron.

Coyle, the biggest center on the roster at 6-foot-3 and 220 pounds, gives the Bruins a fourth center who excels at puck possession, and plays effectively at both ends of the ice.

“I think that’s one of the reasons we were successful,” said Cassidy, who coached the Bruins to within one win of the Stanley Cup last season. “You’re hard to play against when it’s hard to get the puck away from you. And we’ve got four (centers) who aren’t going to give up the puck, and are defensively responsible when they don’t have it.”

Consistently recognized by teammates as the best player in the Bruins’ just-concluded training camp, Coyle (1-3—4 in three preseason games) loves the idea of being part of a group that can intimidate an opponent before a game has even started.

“When you look up and down the lineup at the team you’re playing, and you see all good-sized guys who can play down the middle of the lineup, it gets to you mentally,” he said. “It’s like, ‘Oh, we’re in a for a long one.’ ”

Bergeron (6-1, 195 pounds) and Krejci (6 feet, 188) aren’t giants, but both are physically solid and exceedingly patient. Neither is afraid to absorb some contact while teammates get into scoring positions, and their vision and skill sets allow them to execute the sorts of shots or passes that have made them two of the most productive players in franchise history: Bergeron’s 813 points (in 1,028 games) rank sixth all time; Krejci is ninth with 643 points in 850 games.

They’re both coming off career years, too – Bergeron with 79 points (despite losing 17 games to injury), Krejci with 73.

“We have a very dominant group through the middle,” said Brad Marchand, Bergeron’s left wing since the 2010-11 Stanley Cup championship season, and a 100-point scorer for the first time last season. “They all have different abilities, different ways they do things.

“(Kuraly) has great speed. (Coyle) is so dynamic, the way he can cut back, and he’s very fast and has very good hands. (Krejci) slows things down and can dangle through anyone, and (Bergeron) can do a bit of everything.”

Cassidy’s plan isn’t foolproof. For one thing, It’s incumbent on someone nailing down the right wing position next to Krejci and left wing Jake DeBrusk because Coyle, also a proven NHL winger, is a viable option there, too. Incoming center Par Lindholm could push Kuraly to wing on occasion. Injuries are a given.

Nobody’s advocating for change, though. The Bruins’ top-to-bottom strength down the middle allows Cassidy to spread ice time on most nights, which is valuable over a long season – especially with Bergeron 34, and Krejci 33.

“It’s not just me and (Krejci),” Bergeron said. “It’s also about the guys doing what you’d call the dirty work – eating big minutes, being responsible both ways, scoring some big goals. (Coyle and Kuraly) are definitely in that mold.

“They’re talented players, too, and they seem to be getting even better. It’s nice to watch.”