ZAGREB, Croatia (AP) -- U.S. Open champion Marin Cilic says his participation in the Australian Open is in doubt because of a right shoulder injury.
The ninth-ranked Croatian said Monday "considering the full recovery and opportunity for practice, it is highly questionable if I will be able to play."
Cilic says he still did not withdraw officially from the Grand Slam tournament that starts Jan. 19 in Melbourne "since there is still a week or so left to see how things will develop."
Cilic, who has had the injury for the past six months, defeated Roger Federer and Kei Nishikori to win his first Grand Slam title in New York in September. He withdrew from several tournaments since, including this week's Brisbane International.