Midfielder Andrea Pirlo looks set to skip Italy's World Cup opener against Paraguay on June 14 with a calf injury and he could even miss the entire tournament.
The 2006 World Cup winner, injured in Thursday's 2-1 friendly defeat by Mexico, will definitely sit out Saturday's final warm-up with Switzerland in Geneva.
"It's an injury which worries me but there's time," team doctor Enrico Castellacci told reporters.
"The intention is to take him to South Africa to see if he can be fit. Maybe not for the first game but before June 13 we can change players in the squad," he added.
The 31-year-old Pirlo, who would have been a definite starter, has left the Azzurri's training camp in the Italian Alps to rest at home but will fly out with the team on June 8.
Coach Marcello Lippi already has a doubt over winger Mauro Camoranesi, who has a knee injury, and the loss of Pirlo for any games at the World Cup would be a big blow to the holders.
Castellacci said Camoranesi was progressing well.
Lippi had already put midfielder Andrea Cossu, left out of the 23-man squad, on alert to go to South Africa if Camoranesi was not fit and the Cagliari man would also be the most like-for-like replacement for Pirlo.
If both Pirlo and Camoranesi are not fit for the tournament, midfielder Antonio Candreva could come in having been in the provisional 30-man squad.
Pirlo's dead ball ability and neat passing were key to Italy's 2006 triumph but he has struggled to impress for AC Milan in the last two years.
New Zealand and Slovakia are also in Group F.
