The tennis federation said early Monday that Rosewall was admitted to the San Camillo hospital.
Rosewall's wife, Wilma, was quoted by Australia's Sydney Morning Herald on Monday as saying the 76-year-old former tennis star suffered no heart or brain damage, but was being kept under observation until he was well enough to return to Australia.
The eight-time Grand Slam winner Rosewall was attending the tournament to receive a golden racket, an award presented annually to former tennis greats. Rosewall won 132 singles titles in his career, including four Australian Opens, two French Opens and two U.S. Opens.
Snow shuts down first stage of Tour of California
The start of the Tour of California was wiped out Sunday because of snow, forcing organizers to cut the event from eight to seven stages.
Before calling off the start, organizers delayed the stage by 2 hours, 45 minutes and shortened the scheduled 118.7-mile road race from South Lake Tahoe to Northstar at Tahoe Resort to 49.2 miles.
When the weather cleared a bit, the 144 riders were signed in at the start and about to compete under a light snowfall, a temperature of 35 degrees and 12 mph wind, but organizers called it off less than a minute before the start. Originally set for 763.8 miles, the race has been cut to 645.1 miles.
The World-Anti Doping Agency will conduct its own independent investigation to determine the source of the leak of an International Cycling Union document that ranks riders at last year's Tour de France on a scale of doping suspicion.
WADA director David Howman informed the agency's executive committee and foundation board at Sunday's semi-annual meeting that he pledged its ''full support'' of the UCI's own investigation into the leak of what it termed ''an internal working document.''
On Friday, French sports daily L'Equipe published what it said was UCI's ''index of suspicion'' for all 198 riders from the 2010 Tour on a grade of zero to 10.
The index rated professional cyclists, with 10 the highest level of suspicion and zero the lowest, on how likely officials felt they were to be using banned substances, based on information taken from blood tests and the athletes' biological passports.