Marko Arnautovic has gone to hospital for a scan on a suspected broken foot that he suffered in West Ham's 3-0 defeat to Wolves.
The Austrian was making his first appearance for the Hammers since the victory over Arsenal on January 12.
He had been the subject of a £35million bid from a Chinese club in the transfer window and was said to be tempted at the financial benefits of moving to Asia.
However, Arnautovic signed a new deal on Saturday to stay at West Ham and was named in the starting line-up on Tuesday night.
It was not a happy return though as Arnautovic limped off midway through the second half following a tackle from Ruben Neves.
He left Molineux on crutches with a protective boot on his right foot and is now on his way to hospital to have a scan to assess the damage properly.
Manager Manuel Pellegrini said: 'It will not be an easy injury. I hope he hasn't any problems but we must review him with an examination.
'It was a hard kick in his foot. I'm disappointed about that and disappointed because we have just 15 fit players.
'We don't have any creative midfielders in this moment so it's difficult playing so many games with the same 15 players.'
