On March 15, 2014, Pelech signed a three-year, entry-level contract with the Islanders. At the time of the signing, he ranked third among OHL defencemen with 54 points in 59 games. Following the Islanders' 2014 training camp, Pelech was loaned to their American Hockey League (AHL) affiliate, the Bridgeport Sound Tigers, to start the 2014–15 season. He spent the entire season with the Sound Tigers and tallied 11 assists through 65 games.
