Morocco midfielder Youssef Ait Bennasser faces a battle to be fit in time for the World Cup after being sidelined for five weeks with a thigh injury.
Stade Malherbe de Caen coach Patrice Garande confirmed the severity of Ait Bennasser's injury, which he sustained in his side's 3-0 victory over Angers in March.
"Youssef will be out for five weeks and should be ready for visit of Monaco [on May 6]," Garande told journalists, as per L'Equipe.
Without Ait Bennasser, Caen were thumped 3-1 at home by Montpellier on Sunday, and after losing three games in a row, the Normandy-based club have dropped to within six points of the relegation playoff spot.
Ait Bennasser's injury leaves him with little opportunity to make a case for inclusion in Herve Renard's 35-man provisional squad, which is due to be confirmed by May 14.
The 21-year-old is currently on loan at Caen from his parent club Monaco, and was included in the Atlas Lions' squad for their recent friendlies against Serbia and Uzbekistan before withdrawing through injury.
He last featured for the North Africans in their 3-1 friendly victory over South Korea on October 10.