Monaco midfielder Joao Moutinho will miss up to six weeks with an ankle injury suffered in his side's draw against Lille.
The Portugal international was substituted just after the hour-mark of Monaco's 0-0 Ligue 1 draw at home to Lille on Friday.
The club confirmed the severity of the injury on Sunday, saying Moutinho would miss between four and six weeks.
Moutinho's injury is a blow to Monaco's chances of reaching the UEFA Champions League group stages.
The 28-year-old is certain to miss his team's play-off against Valencia, who host the first leg on Wednesday.
Monaco are also set to be without Moutinho for their clash against Ligue 1 leaders Paris Saint-Germain on August 30.
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