BOSTON >> When the Boston Bruins take the ice against the St. Louis Blues, they will do it with a core group of veterans who know what it’s like to hoist the Stanley Cup — and have it slip from their fingers.

Patrice Bergeron can still remember the instant euphoria and accompanying adoration from across New England that came after the Bruins outlasted the Vancouver Canucks in seven games to win the Cup in 2011.

He just as easily recalls the emptiness in 2013 when the Bruins lost the final in six games to the Chicago Blackhawks.

“I think it makes you appreciate and makes you understand how hard it is to get to this point,” Bergeron said.

He is one of five current Bruins that were on both of those teams, along with Brad Marchand, Tuukka Rask, David Krejci and Zdeno Chara. Apart from Chara, who was 33 in 2011, Bergeron, Krejci, Marchand and Rask were all in their 20s during both runs. Defenseman Torey Krug was as a member of the ‘13 team that came up short, arriving the season after Boston won it in 2011.

Nine years later Chara is now 42 and the 20-somethings are now grizzled NHL veterans as they prepare to take on the Blues.

It’s cast them all in the leadership role for another youthful and hungry Bruins team, built with many players about to experience this stage for the first time with Game 1 coming up Monday night.

It’s a position they have all willingly accepted.

Chara said this season has been a great teaching tool for them.

“It takes a lot to just get into the playoffs,” Chara said. “We saw a lot of our games went to Game 7. First round. Second round. You have to realize how special it is to be in the final and what it takes. At the same time, you haven’t accomplished anything. You haven’t won anything.”

St. Louis coach Craig Berube knows the Bruins are deep and the veteran players are a key part of the team.

“Chara is still a good player, he’s a force out there, a big guy and he’s difficult to play against,” Berube said. “Overall, their team’s a skilled and fast team and their goalie has played extremely well so far in the playoffs.”

Boston coach Bruce Cassidy, who is in his second season leading the B’s. He struggled in his first go-around as a head coach in Washington, going 47-47-9 over two seasons from 2002 to 2004.

The past two seasons in Boston, Cassidy said, he has gone from being apprehensive about speaking up around his best players to setting an agenda and then leaning on his veterans in the locker room to help implement it.

“I think this leadership group is second to none,” Cassidy said. “I don’t know if I’ll ever have — wherever this career takes me — a group like this to work with. I said that since probably the second week of our job here. These guys are fantastic, and they sure make a coach’s job a lot easier.”

Though he has a reputation of letting his anger get the best of him at times, Marchand said he’s going into his third Cup final with Boston as even-keeled as ever.

“I think when you’re part of a team like that you expect it to last a long time,” he said. “You don’t realize how one change in a team can really drastically affect how things play out. One player change. One injury. One call. You don’t realize what it takes to get back to the finals and how fortunate you are to get there.

“And so this time around I think I’m more appreciative of being here and at the same time more calm, I guess, in a way.”