Hughes was injured in the Devils' 4-1 loss to the St. Louis Blues on Friday. He crashed awkwardly into the boards at 11:35 of the first period, on his fifth shift of the game, after being slightly hooked by Blues defenseman Torey Krug.
New Jersey coach Lindy Ruff said the team is "fortunate" that Hughes wasn't injured worse in the collision.
"He came back, he tried a shift. We got him on his way home to be taken care of by athlete care people back in Jersey," Ruff said. "I think we're fortunate, actually."
The center is tied for the league lead in points (20) with Vancouver Canucks center Elias Pettersson. He has five goals and an NHL-leading 15 assists in 10 games. Through Saturday, his 12 power-play points were second in the NHL. Hughes has also helped the Devils to the league's best man-advantage unit, which had a 43.6% conversion rate before Sunday's action around the league.
"It's tough," Devils forward Curtis Lazar said after the team's loss in St. Louis. "Look at the start he's had. I'm not going to lie, we were a little dejected when it happened. But, again, you've got to kind of turn the page when you realize he's not coming back."
New Jersey is also without captain and center Nico Hischier, who missed his fourth consecutive game Sunday with an upper-body injury.
"Every team has to deal with injuries," Ruff said. "We're dealing with a couple of key injuries. At the same time, it's a great opportunity for other guys to step in."