Sunderland boss David Moyes has warned Jordan Pickford's suitors not to expect a fire-sale price after confirming the club will only consider offers of around £30million.
The 23-year-old goalkeeper has enjoyed a stunning season for the relegated Black Cats, also earning a call-up to the senior England squad, and is being eyed by several potential buyers.
Everton are reportedly the latest, but Moyes said: "It would need to be a really, really big offer.
"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."
Asked if the Washington-born keeper's price tag would be in the region of £30million, Moyes replied: "Yes."
Given the interest in him, Pickford could make his final appearance in a Sunderland shirt at champions Chelsea on Sunday, having redeemed his costly and uncharacteristic error in the 2-0 home defeat by Swansea by turning in another fine individual display as the Black Cats went down by the same score at Arsenal in midweek.
Moyes said: "I feel bad talking about him so much, but I think he has been the highlight and the positive we can really mention.
"For a young boy to break in and actually become an England international, inasmuch as he was called up for the squad, Jordan has been excellent.
"His performance the other night was fantastic, it really was. Probably our biggest disappointment recently was the Swansea game and Jordan was the one. I said on that day, it was nearly as if, 'Oh, Jordan's made a mistake!'.
"Jordan had probably been the only person who had hardly made a mistake the whole season, he had been so good. But the other night everything was nearly perfect, his performance was so good - and we'll need him again this weekend, I've got to say."
Moyes will sit down with owner Ellis Short and chief executive Martin Bain next week to further discuss the blueprint he has handed over suggesting the way forward for the club, and the extent to which Short accepts his plan and is prepared to back it could determine his continued presence in the job.
The Scot said: "Well, I have put it to Ellis and the Board and we will sit down and talk, that was the plan.
"We met a couple of weeks ago and we said the best plan would be to meet again after the end [of the season], so we will do that over the next few days."
Meanwhile, Moyes has revealed a Football Association probe into his "slap" comments to a female reporter is ongoing after he requested a personal hearing.
Reading from a prepared statement, he said: "The matter has not been determined as the commission is going to hear further legal comment from the parties."