Influential Italy midfielder Andrea Pirlo is facing a race against time to prove his fitness for Italy's FIFA World Cup™ defence after suffering a calf injury in yesterday's friendly defeat to Mexico.

Pirlo has been ruled out of the Azzurri's final warm-up match against Switzerland in Geneva tomorrow after picking up the injury that could rule him out for up to three weeks.

Pirlo's injury is something that worries me but fortunately there's time.

Italy's team doctor

Italy team doctor Enrico Castellacci admitted the injury was a concern to the medical team but was prepared to give the 31-year-old every opportunity to feature in South Africa.

"Pirlo's injury is something that worries me but fortunately there's time," Castellacci told Sky Italia. "Every physique reacts in a different way, and Pirlo will be monitored day by day."

Pirlo will travel with the rest of the squad to South Africa following tomorrow's game against the Swiss, but might be unavailable for the Azzurri's opening game against Paraguay on 14 June.