Tennis: Australian Open doubt for Federer

The Australian Open's mobile hospital unit is once again overflowing, with world men's tennis No 1 Roger Federer heading the growing list of star-studded patients.

In what has become an annual concern for Open officials, players are dropping like flies.

Federer said: "After arriving in Australia last Friday, I came down with a terrible stomach virus and it continued to get worse over the weekend. The doctors have advised me I should take a couple of days off to recuperate so that I am able to be 100 per cent for the start of the Open."

There are concerns about the fitness of Rafael Nadal, who called for a trainer during his 6-0 6-1 loss to Mikhail Youzhny in Sunday's Chennai final.

Amelie Mauresmo withdrew from Sydney with a muscle strain and Lucie Safarova with a sore buttock. Jelena Jankovic has a thigh injury and Li Na a knee injury.

- AAP