The New York Islanders have signed defenseman Johnny Boychuk to seven-year, $42 million contract extension.

Boychuk, 31, earned $3.6 million this season and would have been an unrestricted free agent this summer. The Islanders acquired the veteran blueliner from the Boston Bruins on Oct. 4, 2014, in exchange for a pair of second-round picks in 2015 and 2016 and a conditional third-round pick in 2016.

Defenseman Johnny Boychuk has signed a seven-year extension with the Islanders worth $42 million. Mike Stobe/NHLI/Getty Images

Boychuk has seven goals and 25 assists for 32 points, including a plus-17 rating, in 59 games for the Islanders this season. Since his arrival in New York, Boychuk has been a major contributor.

"Johnny's influence in our dressing room, both on and off the ice, has been immeasurable," Islanders general manager Garth Snow told the team's website. "His veteran presence is an asset that we are thrilled to help lead our club."

In his sixth NHL season, Boychuk's $6 million per season will match the salary of Islanders captain John Tavares.

"Ever since I came to the Islanders, the organization has been incredible to both myself and my family," Boychuk told the team's website. "I am proud to be an Islander and look forward to competing every night in front of such a passionate fan base for many years to come."

Bruins general manager Peter Chiarelli decided to trade Boychuk, a key member of Boston's 2011 Stanley Cup championship team, before the start of this season, knowing the would-be UFA would earn at least $6 million per season, which was a salary Boston could not handle with its cap constraints.

Boychuk's accomplishments on the ice are evident, but his personality and work ethic off the ice have become infectious for the Islanders.

"He's got a great personality. He's a throwback kind of guy, and I like to have that type of guy in our room," Islanders coach Jack Capuano said in February. "He knows when to loosen some guys up and is real serious when he needs to be."

In February, the Islanders also agreed on a seven-year, $38 million contract extension with 23-year-old defenseman Nick Leddy.