West Ham’s record singing Andre Ayew faces a “significant rehabilitation period” due to a thigh injury.

The Ghanaian recently joined the Hammers, who are 11.00 for a top-four finish, from Swansea for a fee of £20.5m and made his league debut on Monday at Chelsea.

However, he lasted only 35 minutes as his side went down 2-1 at Stamford Bridge.

Ayew’s injury occurred as he chased Eden Hazard and after having a scan on Wednesday afternoon, the club’s head of medical and sports science team, Stijn Vandenbroucke, confirmed the blow.

The medic says it is too early to put a date on when the 26-year-old will be ready to play again but he will be unavailable for first-team coach Slaven Bilic for some time.

“Andre Ayew injured his right thigh at Chelsea on Monday and underwent a scan on Wednesday afternoon,” Vandenbroucke told whufc.com.

“The medical team will now assess the results with a leading consultant before drawing any conclusions.

“My first thought and priority is with the player and his physical and mental wellbeing.

He has suffered a significant injury and it is imperative that we do not rush to conclusions and we receive the correct diagnosis by consulting top specialists.

He added: “At this time, it is too early to put a timeframe on his potential return date but Andre is facing a significant rehabilitation period.”

West Ham continue their Europa League campaign on Thursday with a trip to Romanian side Astra Giurgiu, a game they are 1.70 to win, with the draw 3.50 and their opponents priced at 4.33.