Nabokov, 38, started Saturday but left in the first period of the game against the Detroit Red Wings with a groin injury. Newsday projects that Nabokov will be sidelined for at least four weeks, but adds there are no plans to look outside the organization for goaltending help at this time.
Nilsson, the Islanders' third-round pick (No. 62) in the 2009 NHL Draft, is 3-6-1 with a 3.57 goals-against average and .880 save percentage at Bridgeport. He'll back up Kevin Poulin, who has started three of New York's past four games in goal and now assumes the starter's role.