Goalie Marc-Antoine Dufour, 18, forwards Cameron Bisson, Tyler Dam, Johnny Foley, Zac Thususka and Evan Gallant were given the news Sunday morning.
It leaves the Islanders with 25 players. Defenceman Pierre-Olivier Joseph is attending camps with the Arizona Coyotes while forward Adam Marsh will join him Sept. 5.
Dufour (Valleyfield, Que.), Gallant (St. Stephen) and Thususka (Summerside) will be junior A affiliate players.
It leaves the Islanders with two goalies, nine defencemen and 14 forwards vying for roster spots.
General manager Jim Hulton said he liked what he saw out of Dufour, but decided to go with returnee Matthew Welsh and rookie Dakota Lund-Cornish.
“He had a really, really good camp, but to me, it doesn't make much sense having two ’99 goalies,” Hulton said. “Dakota had a really good camp as well. We’re fortunate in the fact that, we think, we finally have some really good goaltending depth in our organization.”
The trade window closes Monday morning while there is a waiver process for 19-year-old players who are not signed with teams on Tuesday.
Seacow Pond’s Brad Morrissey, who the Islanders drafted in the third round in June, has verbally committed to the University of Maine.
“It’s a setback, but it’s not a closed door,” Hulton said. “He has two years of high school before he could even grace the doors of Maine. . .
“He remains our property for this level and we’ve seen lots of kids in the past changed their mind.”