Berube, 25, played 14 games with the Islanders last season, posting a 3-2-2 record with a 3.42 goals-against average and a .889 save percentage. The Repentigny, QC, native won a Calder Cup Championship in 2015 with the Manchester Monarchs of the American Hockey League. Selected by the Los Angeles Kings in the fourth round (95th overall) of the 2009 NHL Draft, Berube made his NHL debut with the Islanders in 2015-16 after being claimed off waivers at the beginning of the season.
Bischoff, 22, scored 32 points (five goals, 27 assists) in 38 games last season, his senior year at the University of Minnesota. He was named the Big 10 Defensive Player of the Year and was selected to the Big 10 First All-Star Team. Selected by the Islanders in the seventh round (185th overall) of the 2012 NHL Draft, Bischoff made his professional debut last season with the Bridgeport Sound Tigers (AHL), scoring three points (two goals, one assist) in six games.
Grabovski, 33, missed the 2016-17 season due to injury. He spent the previous two seasons with the Islanders, totaling 44 points (18 goals, 26 assists) in 109 games. In 534 career NHL games with the Montreal Canadiens, Toronto Maple Leafs, Washington Capitals and Islanders, Grabovski scored 296 points (125 goals, 171 assists). He posted a career-best 58 points and 29 goals in 2010-11 with Toronto.