West Ham midfielder Cheikhou Kouyate has been ruled out for six weeks with a groin injury.
Kouyate, 24, suffered the injury during Saturday's 3-1 win over Liverpool.
Scans have revealed the 24-year-old Senegal international faces a spell on the sidelines.
"Bad news. C.Kouyate will be out for 6 weeks," Hammers co-chairman David Gold wrote on Twitter. "He will probably miss 5 games and might be available for Aston Villa at home 8 nov."
|Premier League games Kouyate might miss|
|27 September||Manchester United (a)|
|5 October||QPR (h)|
|18 October||Burnley (a)|
|25 October||Manchester City (h)|
|1 November||Stoke (a)|
Kouyate could miss up to five Premier League games, starting with Saturday's trip to Manchester United.
He is also set to miss Senegal's next two 2015 Africa Cup of Nations qualifiers, at home to Tunisia on 10 October and then away to the same team five days later.
He joined West Ham on a four-year deal from Anderlecht in the summer, and had played in all five league games prior to his injury.