Everton manager Sam Allardyce accepts he may be forced to sell star midfielder Ross Barkley in January.

Barkley, 24, last played competitively in May but is nearing a return from a hamstring injury.

The England international is yet to re-sign with Everton despite his contract expiring in 2018, and Allardyce said Barkley could be sold next month.

"It's a difficult one," he said. 

"I haven't had the opportunity yet to find out the truth, or the whole scenario, to ask, 'Where does it lie?' and then make a decision one way or the other.

"I'm not in control of that in too many ways. If someone comes in during January and says, 'Here you go' [with an offer] and the club says, 'Look, if he's not going to sign for us this has to be the case,' then I accept that."

Everton have jumped to 10th in the Premier League thanks to a four-match unbeaten run.

Allardyce said he would welcome Barkley, who is expected to be fit in January, back if the midfielder wanted to remain at Goodison Park.

"If Ross stays, and stays until the end of the season, and I feel he is giving 100 per cent to the team, like he has done since he was a kid, then he is an available asset until he leaves on a free transfer," he said.

"I would hate that to happen, but it might do."