Konstantin Koltsov, the Belarusian former pro ice hockey player and boyfriend of tennis player Aryna Sabalenka, has died at the age of 42, Russian club Salavat Yulaev said in a statement on Tuesday.

Forward Koltsov played for the Belarus national team in the 2002 and 2010 Olympics and spent parts of three seasons with the National Hockey League's Pittsburgh Penguins from 2002 and 2006.

"It is with deep sorrow that we inform you that the coach of Salavat Yulaev, Konstantin Koltsov, has passed away," Salavat Yulaev, which is based in the Russian city of Ufa, said in the statement.

"He was a strong and cheerful person, he was loved and respected by players, colleagues, and fans. Konstantin Evgenievich forever wrote himself into the history of our club.

"May he rest in peace."

Renowned for his speed on the ice, Koltsov won the Russian Super League title with Salavat Yulaev in 2008 and more recently returned to the club as an assistant coach.

Sabalenka and Koltsov were first linked in June 2021, according to People magazine, and the world number two has frequently posted photos of them together on her Instagram account.

"I love you @koltsov2021," she wrote in one post that included heart and other emojis.

"Happy birthday my love. You are my dearest person, my best friend and my strongest support. Peace be with you, strength, patience and health.

"I hope we will have everything we planned I love you."

Koltsov also applauded Sabalenka after the Belarusian won her second consecutive Australian Open title in January.

Sabalenka lost in the last 16 at Indian Wells last week and is scheduled to play her first match at the Miami Open on Friday.