The deal has an average annual value of $4.4 million and ties Marino, who is entering the final year of his entry-level contract, to the Penguins through the 2026-27 season.
"I don't know if it's really hit me yet," Marino said after signing the deal on the eve of training camp. "But a really cool experience, just thinking back to when you were skating as a kid and your parents were taking you to the rink. All those sacrifices that paid off. It was pretty cool to experience it with my family, friends and teammates."
Signed, sealed, delivered. He's ours. pic.twitter.com/SrhGF1Nbx9— Pittsburgh Penguins (@penguins) January 3, 2021
Marino, 23, was a steadying force on the Penguins' blue line last season, posting six goals and 20 assists with a plus-17 rating as a rookie and finishing eighth in Calder Trophy voting. He was fourth in points among rookies in 2019-20.
"We are very fortunate to have a young, skilled defenseman like John in our organization," Rutherford said in a statement. "His rookie season proved he is a top-four defenseman with great hockey sense. We were impressed with his strong defensive play and look forward to watching him develop offensively."
The deal caps a meteoric rise for Marino, who was acquired from the Edmonton Oilers in July 2019 in exchange for a sixth-round pick. The move gives Pittsburgh added long-term security on the blue line. Marcus Pettersson signed a five-year contract extension last January.
"I think it's important to stay with a team that really wants you, wants you to develop and progress as you go along in your career," Marino said. "It seems like a great fit with the coaches and the teammates. You might not have some of the same guys around later in your career, but you definitely want to be with an organization that wants you."
The Associated Press contributed to this report.