“It's impossible to believe! I will always remember your cheerful smile and our matches for the national team in the Davis Cup! Rest in peace, my friend, ”Kafelnikov wrote on his Twitter.

Volkov passed away at the age of 52.

Volkov during his career won three tournaments and rose to 14th place in the ranking of the Association of Professional Tennis Players (ATP). In 1993, he reached the semifinals of the US Open, and in 1994 and 1995 played in the Davis Cup final for the Russian team.

Later, he also worked as a national team coach.

Earlier it was reported that two-time Olympic medalist in swimming Andrei Smirnov died at the age of 62.