Sunderland will only consider offers of about £30m for goalkeeper Jordan Pickford, says boss David Moyes.
Pickford, 23, has impressed this season, despite the Black Cats' relegation from the Premier League, and won a first England call-up in October.
Everton are rumoured to be interested in Pickford and are prepared to offer £15m for the England Under-21 international.
"It would need to be a really, really big offer," said Moyes.
"I have said all through the season that sometimes on your journey, you may have to sell to improve.
"But I have heard some really derisory sort of figures getting mentioned, and it wouldn't be any of those figures, I can tell you that.