World number four Stefanos Tsitsipas admits he is unsure if he will be fit to play at the Australian Open starting on 17th January in Melbourne.
Greece’s Tsitsipas was beaten 6-7 (5-7) 6-3 6-3 by Argentina’s Diego Schwartzman at the ATP Cup in his first singles match since elbow surgery.
The Australian Open starts on 17 January in Melbourne.
Tsitsipas won the first set against Schwartzman, before the 29-year-old rallied to win the match and secure victory for Argentina.
Earlier, his team-mate Federico Delbonis beat Greece’s Michail Pervolarakis 7-6 (7-5) 6-1.
Argentina will face Poland on Wednesday in their final group D match with a place in the semi-finals up for grabs, after Poland beat Georgia 3-0.
World number nine Hubert Hurkacz, from Poland, recovered from a set down to beat Georgia’s Aleksandre Metreveli, the world number 570, 6-7 (5-7) 6-3 6-1.
Pablo Carreno Busta and Roberto Bautista Agut won their respective singles ties in straight sets to ensure victory for Spain over Norway.
Bautista Agut upset Norwegian world number eight Casper Ruud 6-4 7-6 (7-4) after Carreno Busta had beaten Viktor Durasovic 6-3 6-3.
Chile’s match with Serbia will go to the deciding doubles with the score tied at 1-1 after the singles rubbers.
After Filip Krajinovic defeated Alejandro Tabilo 6-4 3-6 7-6 (7-5) to give Serbia the early advantage, team-mate Dusan Lajovic was forced to retire injured from his match with Cristian Garin with the Chilean winning 4-6 6-4 3-0.
