West Ham manager David Moyes believes a transfer fee for midfielder Declan Rice would dwarf the £106 million Chelsea just paid Benfica for Argentina World Cup winner Enzo Fernandez.
Rice has been strongly linked with Premier League leaders Arsenal, among others, and has said himself he wants to play Champions League football at some stage of his career.
Speaking after West Ham's 1-1 draw at Newcastle on Saturday, Moyes said: "Undoubtedly Declan is going to be a top player. He'll be a British transfer record if he ever leaves West Ham
"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."
Rice came through the youth ranks at West Ham and has made over 200 appearances for the Irons in all competitions.
The 24-year-old also has 39 caps for England and is a key part of Gareth Southgate's side.
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Declan Rice was linked with Arsenal in the recent transfer window, but the Gunners ultimately turned to Chelsea's Jorginho instead.
Meanwhile, Rice admitted in December that he wants to play Champions League football one day and conceded that he would probably have to leave West Ham in order to fulfil that objective.
West Ham were also linked in December with a move for Manchester United right-back Aaron Wan-Bissaka.
