Fulham midfielder Joao Palhinha's contract does not contain a release clause.
The defensive anchorman is being linked with a move away from the Cottagers.
Despite an excellent first season back in the Premier League, Fulham may lose a key player if big clubs come calling.
West Ham United are seeking Palhinha as a replacement for Declan Rice, while Manchester United are also linked.
Per talkSPORT, Palhinha may have a release clause in his deal, which means clubs will have to pay a hefty fee to secure his signature.
The 27-year-old has a deal that expires in 2027, which means Fulham hold all the cards.
However, Fulham owner Shahid Khan's son Tony Khan denied the rumours on Twitter.