Martinez insists the former Manchester United midfielder will notbe soldt for “any money”.
“I wouldn’t sell him for any money in the current market,” said Martinez.
“The value that you can give to him… clearly for whatever reason he didn’t fit in another football club, but in another football club, in our football club you can really see the value that he has, the effect he has on other players.
“Being English is an incredible, incredible premium and I want to see him go from strength to strength because I know there is so much more to come from him.
“You saw the delivery, the work rate. I think we have ten goals a season to get into his game very quickly. And I think he can go even further.”