West Ham United boss Slaven Bilic admits that it's a big blow for the club to lose record signing Andre Ayew for four months.

Ayew, who signed for the Hammers in a £20.5million deal from Swansea City, suffered a thigh injury in the 2-1 defeat to Chelsea on Monday night.

Speaking to BT Sport after West Ham's 1-1 draw in the first leg of their Europa League play-off against Astra Giurgiu, Bilic said: "It is not good and he needs surgery.

"Four months is a big, big blow for us but he'll be back.

"If he's a good healer he can be back before Christmas. We have to cope with it. There's no point moaning about it."