Brighton manager Chris Hughton has said that Shane Duffy won't come cheap, with various Premier League clubs reportedly interested in his services.
The Republic of Ireland international signed a new five-year deal, alongside central defensive partner Lewis Dunk, to remain at the club until 2023.
After a string of impressive Premier League performances, including two goals in ten appearances, his value has rocketed form the initial £4m they paid for him from Blackburn Rovers in 2016.
"Any interest in the players that are playing very, very well, there would be a premium that goes with that," Hughton told 'Sky Sports'.
"Whether that puts some teams off, I don't know, but (Duffy's) a player that's done really well for us, and I still think there's more to come from him.
"You want to buy players and you're looking at individual players, and of course everybody's price goes up, and that would be exactly the same for us.
"As a club, what you have to do is protect yourself, and firstly he deserved (his new contract) for the performances that he's put in.
"We're conscious of how well he's done for us and it's a good opportunity for this club to protect an asset."