All three are expected to be available Sunday when the Islanders face the Red Wings in Detroit. With forwards Shawn Bates (groin), Oleg Kvasha (ankle) and Petteri Nokelainen (knee) sidelined, New York will likely play 11 forwards and seven defenseman.
Gervais, a sixth-round pick in 2003, has yet to play in the NHL. The 21-year-old Quebec native leads AHL defensemen with eight goals.
"We want to see how Bruno can do at this level," Islanders coach Steve Stirling said. "He's earned a shot."
Nilsson, the 15th overall pick in the 2003 draft, has two goals and four assists in 25 games this season -- his first in the NHL. He has gone without a point in 17 of his last 21 contests.
"He played banged up a bit for a few games and then we gave him a few days of rest," Stirling said of the 20-year-old center. "Right now, he's not on one of our top forward lines, and Robert is too young and too talented to be sitting on the bench. We need him playing a lot.
"He'll get plenty of ice time in Bridgeport ... and then we'll see. Make no mistake: Robert is going to be a big part of the Islanders for a long time," he said.
Smith made his Islanders debut in a 4-3 home loss to Philadelphia on Tuesday and was then returned to Bridgeport the following day.