Lleyton Hewitt's first claycourt outing in two years ended painfully as he twisted his ankle during a 3-6, 6-3, 7-6 defeat by Brazilian Marcos Daniel in the opening round of the Poertschach International on Monday.
The Australian, who has suffered a run of bad luck over the past two claycourt seasons with a series of injuries, could miss his second successive French Open if the latest setback turns out to be serious.
Playing his first match on the ATP tour for almost two months, Hewitt looked in good physical shape in the Austrian city until the closing stages of the contest.
Trailing 4-3 in the third set tiebreak, the former world number one twisted his ankle and immediately collapsed behind the baseline clutching his foot in agony.
He remained rooted to the baseline before being attended to by a trainer.
The second seed returned to complete the match but failed to win another point as Daniel secured victory with an easy forehand.
Hewitt now faces a race against time to get fit for the season's second Grand Slam tournament, which begins at Roland Garros in Paris on Sunday.
