West Ham midfielder Dimitri Payet will be sidelined for up to three months after suffering an ankle injury against Everton last weekend.
Payet had made an impressive start to his time at West Ham following his £10.7 million ($16 million) move to the Premier League club from Marseille in the close-season.
But the 28-year-old France international, who had scored five goals in 14 appearances, was forced off in the 50th minute after a challenge from Everton's James McCarthy in Saturday's 1-1 draw at Upton Park.
And Jack Sullivan, the son of Hammers co-owner David Sullivan, revealed the extent of Payet's injury on Twitter.
"Sadly Payet will be out for about 3 months! Huge miss for the team. How the Everton player didn't get sent off amazes me!!" Sullivan wrote.
West Ham's Ecuador forward Enner Valencia was also injured against Everton and boss Slaven Bilic is awaiting the results of a scan on his ankle problem.