Kivlenieks, a goalie who wore No. 80 for the Columbus Blue Jackets, died in a fireworks accident. He was 24.
Dubois played with Kivlenieks on the Blue Jackets for two seasons before the forward was traded to the Jets on Jan. 23 with a third-round pick in the 2022 NHL Draft for forwards Patrik Laine and Jack Roslovic.
After learning of Kivlenieks' death, Dubois posted a picture of him on Instagram with the caption, "RIP 'Kivvi'. You were a great person and an unbelievable friend to have."
Dubois wore No. 18 with Columbus and switched to No. 13 after he was traded to Winnipeg. He scored 21 points (nine goals, 12 assists) in 46 games last season.
Kivlenieks was signed by Columbus as an undrafted free agent May 25, 2017. He was 1-1-0 with a 3.40 goals-against average and .901 save percentage in two games with Columbus last season, and 2-2-2 with a 3.09 GAA and .899 save percentage in eight NHL games (six starts) the past two seasons.
A memorial service held for Kivlenieks on July 15 was attended by Blue Jackets coaches and players, Kivlenieks' parents and relatives from Latvia.
Blue Jackets goalie Elvis Merzlikins said at the service that he and his pregnant wife, Aleksandra, were hugging about 20-30 feet behind Kivlenieks when he was hit in the chest with a stray mortar. Merzlikins and Kivlenieks were in Novi, Michigan, for the July 4 holiday weekend to celebrate the wedding of goaltending coach Manny Legace's daughter, Sabrina.
"He saved my (unborn) son. He saved my wife and he saved me," Merzlikins said. "He saved many lives. … If that wouldn't have been me, my wife or son, it would've been 50 other people. He died a hero. And that's not me saying it. That was the doctor saying it. If he would just sit, it wouldn't have happened. … I just wanted to let you know that he was a hero. He saved a lot of lives.
"Matiss wasn't my friend. He was my little brother."
