Semyon Varlamov took warmups for New York and was expected to start but was instead placed into NHL COVID-19 protocol. Colin Cooper, who played four seasons with Mount Royal University in Calgary from 2015-19, was the emergency backup.
"'Varly,' obviously he was scheduled to play," Islanders coach Barry Trotz said. "He warmed up feeling fine, but obviously while we're in Canada you have to test and we got the results, basically, I think there was maybe about 10 minutes before we were going back on the ice. So 'Sorokie' had to go in there last minute."
Ruzicka put Calgary up 1-0 at 9:58 of the first period. He shot by Sorokin's blocker after taking a centering pass from behind the net from defenseman Rasmus Andersson.
"To be honest, I don't really care about the points," Ruzicka said. "I care that we won the game. That's six in a row."
Dobson tied it 1-1 at 17:07 on a power play when his point shot deflected off the stick of Flames forward Blake Coleman. The goal came after New York had hit the post three times earlier in the period.
Chris Tanev gave Calgary a 2-1 lead at 18:08 when his wrist shot from the high slot deflected off the stick of Islanders forward Zach Parise. Tanev has scored seven points (two goals, five assists) in a four-game point streak.
Mangiapane made it 3-1 at 15:32 of the second period when he redirected Ruzicka's pass by Sorokin. Mangiapane has scored seven points (five goals, two assists) in a five-game point streak.
"I was battling in front there and saw him pick the puck up and I just had my stick on the ice and he just hit it off my stick and it went in," Mangiapane said.