France forward Karim Benzema was absent from Real Madrid's training session on Wednesday, hours before Didier Deschamps announces his World Cup squad, an AFP journalist witnessed.
Ballon d'Or winner Benzema has missed four games due to a thigh problem with Les Bleus coach Deschamps naming his 26-man list at 7pm GMT later on Wednesday.
"He has not been able to come back from this little irritation, it is nothing major," Real Madrid coach Carlo Ancelotti told reporters.
"He has tried, but it has not been possible," he added.
Deschamps, who guided France to the 2018 title, is already without injured midfielders Paul Pogba and N'Golo Kante.
Experienced centre-back Raphael Varane will not feature before the World Cup for his club Manchester United due to a thigh problem but has not been ruled out of the competition.
Deschamps's side start the defence of their title on 22 November against Australia, before also playing Denmark and Tunisia in Group D.