The New York Islanders looked like heavyweight contenders in the season opener only to be knocked out in short order two days later. The Islanders aim to pick up themselves off the mat Monday when they host the Boston Bruins in Uniondale, N.Y. Coach Barry Trotz’s charges cruised to a 4-0 romp over the New York Rangers on Thursday before their rivals put them on the business end of a 5-0 shellacking at Madison Square Garden. Goalie Semyon Varlamov sustained an injury in warmups prior to Saturday’s loss, leading to the surprise NHL debut of Ilya Sorokin -- and it all went downhill from there. While Trotz did not provide an update on Varlamov after the game, he did reflect on the Rangers scoring four of their five goals off turnovers and his team’s nine penalties serving as a major deterrent for any comeback bid. “The first four goals are all stuff that we did,” Trotz said. “Turnovers, bad plays, poor execution. We were junk.” Trotz particularly took issue with top-line center Mathew Barzal committing three offensive-zone penalties. “That can’t happen. That’s a sin to me,” Trotz said of Barzal, who signed a three-year, $21 million contract earlier this month. Barzal recorded team-leading totals in assists (41) and points (60) last season and had 12 and 17, respectively, during the Islanders’ playoff run to the Eastern Conference final. The 23-year-old collected two goals and an assist in three meetings with Boston last season. The Islanders have struggled mightily against the Bruins of late, posting a 1-7-2 record in the last 10 meetings. The lone victory in that stretch was a 3-2 shootout win in Boston on Dec. 19. The Bruins were two seconds away from reaching the shootout round on Saturday afternoon before allowing an overtime goal in a 2-1 road loss to the New Jersey Devils. Captain Patrice Bergeron had an assist in Boston’s 3-2 shootout win over New Jersey on Thursday before scoring the lone goal two days later. “It’s a work in progress,” Bergeron said. “You’re trying to work on a lot of things, the system, and make sure you jell as a team. It’s early in the year. You take the three out of four (points) but you always expect more and expect to be better. “I think working on our consistency is gonna be something (important) and being good for 60 minutes, that’s what you need in this league.” Bergeron scored in overtime of a 3-2 win against the Islanders on Jan. 11, 2020. The four-time Selke Trophy recipient has 21 goals and 34 points in 47 career encounters versus the Isles. Tuukka Rask sports a sterling 17-5-1 record with a 1.88 goals-against average and .937 save percentage in 24 career games against New York. One of his two shutouts against the Islanders came in a 25-save performance in a 4-0 win last Feb. 29. Jaroslav Halak, who played with the Islanders from 2014-18, made 29 saves for Boston on Saturday.