France international full-back Djibril Sidibe is a major doubt for Monaco ahead of Saturday's French League Cup final against Paris Saint-Germain, his club said on Tuesday.
The 24-year-old injured his ribs in the 3-1 World Cup qualifying victory in Luxembourg last Saturday.
Monaco said Sidibe will be gradually eased back into training over the coming days, meaning he may not recover in time for Saturday's final in Lyon.
His absence would be an added headache for Monaco coach Leonardo Jardim as star Colombia forward Radamel Falcao is already a doubt due to a hip injury.
Fabinho is suspended for the match while Argentine forward Guido Carrillo and Brazilian midfielder Gabriel Boschilia are out injured.