The 26-year-old forward, who was a restricted free agent, scored 38 points (16 goals, 22 assists) in 43 games with the Red Wings last season, missing 28 games because of injuries.
"The process was a long process, but my agent (Pat Brisson) was telling me that things were going the right way," Mantha said. "So, I kind of needed to trust him at that time. Even us not filing for arbitration, again, it was my agent's call. He said things were going in the right direction. My agent said,] 'I need you to trust me, trust Stevie. He's a man of his word so we'll get it done.'"
***[RELATED: [NHL Free Agent Tracker]*
It's the longest contract a Red Wings player has signed since Steve Yzerman became general manager April 19, 2019. Detroit (17-49-5, .275 points percentage) had the fewest points in the NHL last season and have missed the Stanley Cup Playoffs for four consecutive seasons.
"Obviously he's one of our best players, a key player on our team," Yzerman said Wednesday. "With all of our younger players, and I consider Anthony one of our younger players, we're trying to build around this group and each contract that we do, we try to make it work within what we're trying to do. … But our intention is to keep these young players around. We were able to work out a contract, it turned out to be four years, which I was comfortable with the length and both Anthony and his representation were comfortable with it as well."
Mantha said he is appreciative of the faith the Red Wings have shown in him.
"Everyone knows we're in a rebuild phase," Mantha said. "[Yzerman] signing me to a four-year deal also tells me he sees me as part of the future of the team, part of the guys who's going to help the team win, and that's the pressure that comes with it."