A fever-stricken Nadal was dumped out of the semi-finals of the Qatar Open last week by Russian Nikolay Davydenko and delayed his arrival in Melbourne to try to shake off the illness.
Nadal's struggles had raised fears the 24-year-old Spaniard's bid to hold all four grand slams simultaneously might be in jeopardy, with doubts over his ability to last seven matches in the often oppressive heat of a Melbourne summer.
Heat was the least of Nadal's problems on a damp but muggy Tuesday, as slippery conditions on court curtailed his practice session after about half an hour at the venue's Margaret Court Arena.
Nadal scooped the French, Wimbledon and U.S. Open crowns last year and will strive for an Australian Open triumph to become the first man since Rod Laver in 1969 to hold all four slams at the same time.
Leading women's players Venus Williams and Australian Open finalist Justine Henin also warmed up, while men's defending champion Roger Federer and world number three Novak Djokovic were scheduled for training sessions later Tuesday.
Players' hopes of acclimatising to Australia's summer heat on outdoor courts may come to nothing this week with showers and cool temperatures forecast throughout.
The Australian Open starts Monday.
(Reporting by Ian Ransom; Editing by Alastair Himmer)