West Ham boss David Moyes can see captain Declan Rice commanding a British record transfer fee.
Chelsea signed Benfica midfielder Enzo Fernandez for £107m on Wednesday, making him the most expensive Premier League signing ever.
England midfielder Rice, 24, has played 224 times for the Hammers since his 2017 debut and now captains the club.
"Undoubtedly Declan is going to be a top player," said Moyes.
"He'll be a British transfer record if he ever leaves West Ham."
Rice, who joined the Hammers youth set-up in 2014, only has 18 months left on his contract and has reportedly turned down new deals.
Asked after Saturday's 1-1 Premier League draw with Newcastle if Rice's departure was inevitable, Moyes said: "I hope it's not. I hope he sees his time here."
Argentina World Cup winner Fernandez, 22, had only made 29 appearances in Europe, having joined Benfica last summer from River Plate.
Rice has been a senior international since 2018, first with the Republic of Ireland and then England, while Fernandez only made his Argentina debut in September.
Moyes said: "There's a lot of talk about it and when you see what's going about for the prices, I think Dec will be blowing that out of the water, that's for sure, when it comes around."