The Brad Marchand Era in Boston has come to a close.

The longtime Bruins forward was sent to the Panthers in a trade deadline stunner that officially signaled Boston’s commitment to a rebuild — and helps the Panthers replace Matthew Tkachuk.

Boston receives a conditional second-round pick in 2027 that can turn into a 2028 first-rounder if Florida wins the first two rounds of the 2025 playoffs and Marchand plays in 50 percent of the team’s postseason games.

At 36, Marchand was the oldest member of the Bruins roster, having spent his entire 16-year NHL career with the team until Thursday afternoon.

A four-time All-Star and 2011 Stanley Cup winner, Marchand served as captain for a Boston franchise trying to remain competitive as its window shut.

His 21 goals ranked third on the team, and his 47 points were second-highest for the Bruins.

An infamous agitator, the 5-foot-9 winger kicked his game up a notch in the postseason — two things the Panthers will put to good use as they defend their Stanley Cup title.

Marchand’s addition will help offset the loss of Tkachuk, the gritty heart-and-soul of the Panthers, whose regular-season ended early due to a groin injury suffered at the 4 Nations Face-off last month.

At 39-21-3 entering Thursday’s slate, Florida is atop the Atlantic Division, while the Bruins, at 28-28-8, have seemingly called it quits on any attempt to jockey for a wild card spot.

For the Bruins, the shocking move caps off a long-overdue organizational reset, put off by years of big trades and surprising regular-season success.

Earlier in the week, the Original Six franchise dealt winger Trent Frederic to Edmonton and on Thursday, also sent center Charlie Coyle to the Avalanche and defenseman Brandon Carlo to the rival Maple Leafs.

“Definitely a shocker when I heard that it was Toronto,” Carlo said on TSN in the aftermath of his trade. “What an opportunity for me to go in there and try and help this group win.”