The blonde beauty, ranked 1,086 in the world, evoked comparisons to fellow Russian player Anna Kournikova

Celebrated as the next Anna Kournikova for her talent as well as her physical beauty, Russian pro tennis player Violetta Degtiareva has died at the age of 23.

The International Tennis Federation star apparently suffered heart failure during a training session on Jan. 12. The news went public Wednesday following a Facebook post by her friend and fellow tennis player Anastasia Vdovenco, according to Central European News.

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“I can hardly believe it,” wrote Vdovenco, 20. “Rest in peace.”

Russian media outlets have not specified where she was training, according to CEN, and details about Degtiareva’s heart failure are unknown.

The blonde beauty – who was born in the city of Rostov, near the border with Ukraine in southwestern Russia – was recentlyranked 1,086 in the world as a singles player, with a slightly higher 905 ranking in doubles. The high point of her pro career was reaching the quarterfinals at the ITF-Turnier tournament in Turkey.