Nielsen still has concussion symptoms and Jurcina (hip) is too banged up to try and return with three games to go.
That makes nine regulars who have had their Islanders seasons cut short.
"They made the smart move. It would be stupid to take the risk of trying to come back," Nielsen said. "You see it too many times this year, guys who try to play with small concussions and it ends up way worse. It's not like we're fighting for the playoffs right now."
Nielsen had a breakthrough year, tying an Islanders record with seven shorthanded goals and finishing with 13 goals and 31 assists. He also helped Michael Grabner's breakout year, in which the rookie winger has scored 31 goals, tied for most among rookies.
"We're all excited for next year," Grabner said. "With the way we played the last three months, we showed we can play with anyone. I know (Nielsen) is going to come back strong."
Here's the opening-night roster for the Islanders from Oct. 9, and what's happened to those 20 skaters:
Mark Eaton -- hip surgery, played 34 games
Trent Hunter -- torn MCL, played 17 games
Mike Mottau -- eye/hip, played 20 games
Josh Bailey -- demoted to Bridgeport for a month, played 67 games
Trevor Gillies -- suspended 19 games, played 36 games
Jon Sim -- waived, played 34 games
James Wisniewski -- traded to Montreal, played 32 games
Nino Niederreiter -- returned to juniors, played nine games
Milan Jurcina -- hamstring/hip injuries, played 46 games
Andrew MacDonald -- hand/hip injuries, played 60 games
Frans Nielsen -- concussion, played 71 games
Doug Weight -- back injury, played 18 games
Rick DiPietro -- knee/facial injuries, played 24 games
Dwayne Roloson -- traded to Tampa Bay, played 20 games
"Everyone gets injuries," Grabner said, "but it seems like we had a little extra bad luck."