New Jersey has been outscored 15-4 while losing three straight games and is 2-6-2 in its past 10, including a 4-3 home loss to the Vegas Golden Knights on Tuesday in Nasreddine's debut.
"Listen, would we like to be in a better position? Sure," Subban said. "We're not the only team in this position, but you look at the standings and, I mean, we string together a couple wins and we're back in the mix."
The Devils host the Chicago Blackhawks on Friday (7 p.m. ET; NHLN, MSG+, NBCSCH+, NHL.TV) before beginning a four-game road trip.
"No one has given up on this season," Nasreddine said. "I think that's why they made the big change, and I think everyone's on board. The sooner the better, obviously, but I think once we get this going and guys find the confidence and the buy-in, I think that's when we're going to get some traction."
Subban was acquired in a trade with the Nashville Predators on June 22, one day after the Devils selected center Jack Hughes No. 1 in the 2019 NHL Draft. There were high expectations, especially with Subban expected to play a lead role on the top power-play unit.
That has yet to materialize; Subban has five points (two goals, three assists) and a minus-12 rating, averaging 23:06 in ice time in 27 games this season, and has no points on the power play. He has no points and a minus-10 rating in his past 15 games.
"There's a certain way we want to play, and I think everyone will tell you that everyone in the room has been underachieving," Nasreddine said. "I don't think anyone's happy with their game, and I'm certain that P.K. would tell you the same thing. I think everyone has more to give right now, but moving forward, it's a clean slate for everybody, but everyone has to elevate and get to the next level."
Hughes returned to practice Thursday, and the 18-year-old could play Friday after missing the past three games with a lower-body injury.
"I think with the way we were playing ... I mean something was bound to change, whether it was [the coach] or something else," Hughes said. "It's unfortunate, but it's part of the business. It's the first time I've experienced that. I liked Coach Hynes. He taught me how to compete and how to play hard in the D-zone in the NHL.
"I feel [Nasreddine] is going to do a good job; he knows the team well and he's someone from within."
Subban said he is hopeful Nasreddine, who coached the defense under Hynes, will do all he can to help New Jersey move forward.
"It's only been 48 hours, and being a head coach in the NHL is not an easy job," Subban said. "I think that with the experience [Nasreddine] has with his understanding of the game, it'll be interesting to see his purview on how to make this team better and how to make us better as players."
The Devils qualified for the Stanley Cup Playoffs once under Hynes, losing to the Tampa Bay Lightning in five games in the Eastern Conference First Round in 2018. They finished 27th or worse in the standings in two of the past three seasons and won the NHL Draft Lottery twice, selecting center Nico Hischier No. 1 in 2017 and Hughes in 2019.
Subban said any thought of a turnaround begins with the players.
"We just need to make sure that we're executing and doing the things that we can control," he said. "If you look at the season so far, we've lost a lot of games on those mistakes, mental mistakes, and not really executing the way we need to.
"So there's a coaching responsibility, but there's also a responsibility on the players too."
