Tunisia's top player, Youssef Msakni, is set to miss the World Cup after suffering a knee ligament injury.
The technically gifted attacking midfielder tore a cruciate ligament while playing for Qatari club Al-Duhail in a 5-2 win over Al-Sailiya.
Al-Duhail said in a statement that Msakni "will be absent for three to four months."
Unbeaten during their qualifying campaign, Tunisia are making a return to the World Cup for the first time in 12 years. The Eagles of Carthage will take part in their fifth World Cup but have never moved beyond the group stage.
Tunisia open their Group G campaign against England on June 18 before facing Belgium and Panama.