Buffon, considered one of the best goalkeepers in the world and a lynchpin in the Italian team, was ruled out of Italy’s 2-1 victory over England on Saturday after spraining his ankle during training, causing an inflammation to the tibial tendon.
Enrico Castellacci was quoted by Il Sole 24 Ore as saying that he is “confident” that Buffon will soon recover but could not predict when he will be fully fit to play.
Reports on Sunday said it was unlikely Buffon would be play in the clash against Costa Rica on Friday.
Buffon also suffered a back injury during Italy’s first World Cup game in 2010, ruling him out of the rest of the group stage which saw the team eliminated.
The 36-year-old was a driving force in Italy’s World Cup 2006 victory after not conceding a single goal. Brazil 2014 is his fifth World Cup with Italy.
The Italian manager Cesare Prandelli said on Sunday that "Italy was on the right road" after the win on Saturday, but remained cautious ahead of the game with Costa Rica, who beat Uruguay 3-1 in its first game of the group stage.