To the obvious frustration of manager Manuel Pellegrini, there is still no potential return date as medics attempt to get to the root of the problem.

"Jack continues every week trying to work, but when he works harder he starts to feel pain in his groin," said Pellegrini.

"He is seeing different doctors to see what has happened. He's a player we need a lot, a different player, but if he's not 100 per cent recovered it's difficult for him to work."

Wilshere is set to miss the entire Christmas period as West Ham attempt to build on their 1-0 win at Southampton last time out.

Liverpool's participation in the Club World Cup meant the Hammers had an early winter break but they now have a run of three matches in seven days, with the trip to Crystal Palace on Boxing Day followed by visits from Leicester, on Saturday, and Bournemouth on New Year's Day.

Pellegrini is desperate for his side to rediscover their early-season form after an alarming run saw then slip from fifth to 16th.

"We finished last season very good, we started this season very good. From around 11 or 12 games we lost just one," he added.

"After that, for different reasons, we lost results, we lost our style, we started not playing with the trust that the players need.

"Now maybe we can be more optimistic. In the last four games we won two of them. I hope in the next few games we can continue having good results."

Argentina midfielder Manuel Lanzini returns to the squad after a shoulder injury and Brazilian playmaker Felipe Anderson has recovered from the illness which kept him out at St Mary's, but defender Ryan Fredericks is suspended.

David Martin hopes to shake off a knock to continue in goal, with first-choice keeper Lukasz Fabianski due back from a hip injury by New Year's Day.