Steve Bruce says Hull City will be unable to prevent Tom Huddlestone leaving if any club matches the release clause in the midfielder's contract.
Bruce said after his side's 1-1 draw at Wolves on Sunday that Hull had received no bids for any of their players.
But he confirmed an interest from West Ham in ex-Tottenham man Huddlestone.
The Hull manager said: "I am sure West Ham, like anybody, knows he has a buy-out in his contract and if they get to that figure I am powerless."
Bruce added: "The agents will be touting him around everywhere, which I know they are. But there's nothing I can do."
Huddlestone, 28, capped four times by England, joined Hull from Tottenham for around £5m in August 2013 and has made 78 appearances for the club.