Birmingham boss Lee Clark believes keeper Jack Butland's value will treble if he makes his senior England debut against Italy.
The 19-year-old is in the remarkable position of possibly making his England debut before making an appearance for his club, after spending last season on loan with League Two side Cheltenham.
Clark told the Birmingham Mail: "To be honest with you, I wouldn't want to entertain talk of selling him.
"But you win an international cap, it means are you going to look at a bigger value.
"Six million just gets you a League Two goalkeeper, it doesn't get you a full international - probably treble that, I would have thought."