Reigning world champions Italy suffered big blow as their first-choice goalie Gianluigi Buffon was ruled out of action for an indefinite period with a back injury.

According to a statement released on Tuesday by the Italian Football Federation, Buffon has a bad sciatic problem and it is not sure when he will play again.

The 32-year-old Buffon "felt a pain in his back" during Italy's World Cup opener against Paraguay on Monday and was unable to continue before being replaced by Federico Marchetti at the break.