West Ham confirmed on Thursday that their record signing, Andre Ayew, will be out for around four months because of a thigh injury.
The 26-year-old, who joined for 20.5 million pounds from Swansea this summer, needs an operation after suffering the injury in the first half of his side's match with Chelsea.
West Ham co-chairman David Gold revealed the news in a tweet, saying: "Sad news. Ayew has injured his quadriceps and will need surgery. He will be out for 4 months. Good luck Andre."