Striker Francileudo Santos has been ruled out of Tunisia's World Cup opener against Saudi Arabia because of a shin injury.

The Brazilian-born forward limped out of a friendly with a German invitation team on Wednesday because of the problem, but coach Roger Lemerre said at the time he was not concerned about the 27-year-old's fitness.

However, Tunisia midfielder Mehdi Nafti subsequently revealed the injury is worse than initially thought.

"We know that he is going to miss the first game for sure, and after that we don't know," said Nafti.

"All the staff, the trainers, the players are a little bit sad."

Santos has scored 18 times in 28 internationals for the Carthage Eagles and is sure to be badly missed against the Saudis in Munich on June 14.