Sunderland have had a £5m offer rejected by Hearts for Scotland goalkeeper Craig Gordon.
Craig Gordon flew to Germany for Hearts' pre-season preparations
Neither club would discuss a possible transfer to the English Premier League newcomers for the keeper.
But, while he would not reveal the interested parties, Gordon's agent, Andy Evans, said there had been talks.
"No deal has been agreed at present, but discussions are ongoing between Hearts and at least one Premiership club," he said.
"It is by no means certain a deal will be concluded during the current transfer window.
"But this is the time Hearts can expect a maximum return on Craig as he has two years left on his contract."
The club have their own figure for him and I'm sure when they get it they might look at accepting it
Hearts assistant manager
Gordon has expressed his desire to play in England's top flight at some point in his career.
He rejected a transfer to Spartak Moscow in January.
Hearts assistant manager Stephen Frail said he could understand why the club would be looking for a considerable fee for Gordon.
Speaking on the club's website, Frail said: "I don't sit down and try to value players.
"The club have their own figure for him and I'm sure when they get it they might look at accepting it.
"Obviously, £5m is not in their price, they want more and it's up to them."