Reports on Wednesday night suggested that Spurs rejected a ?22million offer for the Croatian midfielder, who starred in the club's European and domestic campaigns last season.
Tottenham are desperate to hold on to the skilful midfielder, who manager Harry Redknapp recently described as "irreplaceable", but there is a fear that Chelsea could return with an improved bid.
The 25-year-old, who scored four times and provided many more assists last season, signed a new contract in May 2010 and has indicated that he would only be willing to leave the north London club if they change their stance and indicate they are ready to sell him.
But with the likes of now Liverpool midfielder Jordan Henderson recently being bought for ?20million, any transfer for Modric would command a much bigger fee, according to the star's agent, Nikki Arthur Vuksan.
"The price that has been written greatly undervalues the price that the club values him at the moment," he said.
"If there has been a bid of ?22million I am not surprised that the club have rejected it. That figure is near to the fee that Spurs paid for Luka (around ?16million)."
Vuksan said he had not been informed yet that Chelsea have made a bid for his client but admitted that he could receive a phone call in the next few hours stating otherwise.
Vuksan went on to reiterate that Modric is happy at Tottenham, but conceded that he would be willing to talk to Chelsea or any other club, should Spurs chairman Daniel Levy accept a bid for the player.
"The chairman has said he doesn't want to sell Luka and Luka is happy at Spurs," Vuksan added.
"If an offer comes to the club that they are happy to accept, then he is willing to talk to the club. Let's see what happens."
Manchester United have also been linked with a move for Modric, who arrived at White Hart Lane from Dinamo Zagreb three years ago.
Source: Team Talk
Source: Team Talk