Everton playmaker Ross Barkley will not be leaving the club in the January transfer window, according to manager Roberto Martinez.

The Toffees’ form in the first half of the season has not been up to the standard expected and a recent run of one win in the last nine has put pressure on Martinez.

One shining light in their season has been the return of Barkley after the young England international spent a short period out with injury.

Everton, who are priced at 15.00 to win the Europa League, have been struggling of late and a number of top Premier League clubs appear to think that the January transfer window may be the perfect time to pounce.

Martinez has warned defending champions Manchester City, who are thought to be among the potential suitors, that Barkley is not for sale.

The Spaniard believes it is crucial for his side to keep their best players at this stage of the season rather than allowing the squad to be pulled apart.

Martinez said: “This January window for us it is vital we concentrate on recapturing our best form so you can imagine all of our best performers even if they get a lot of attention they are not going to be anywhere.

“We’ve had a tough run of results but it’s up to us all as a club to show what we’re capable of again in the second half of the season. We showed consistently last season what we’re capable of doing and the quality, the talent is there.

“We’ve got three games now at home and that’s really important. We need that positive result that’s going to trigger our season.”