Bernard Tomic says a hip injury, not the flu, is the reason he withdrew from his U.S. Open second-round match against David Ferrer.
The 21-year-old Australian said he became ill a week ago, but also did not want to play because of the injury.
"It was difficult having the flu, but my hip's a little bit not in shape. I'm feeling it inside. So I did the best thing not to play," he said. "I've got to look into it and see what's wrong, because I'm definitely feeling something in that area. For me, it's not good right now."
Tomic had double hip surgery following the Australian Open. However, he indicated the problem is not surgery-related, saying it was a "different area."
"That's all I can sort of say now. I'll get it seen with a specialist, so I get their ideas and I'll decide what's the best idea," he said.
Playing long rallies against a consistent baseliner like No. 4 seed Ferrer was also a consideration.
"It's just something that I don't want to get on court with a player like David and have in the back and potentially cause a lot more problems to myself," said Tomic.
The Australian No. 3 will undergo tests before making a decision about playing Davis Cup.