The Blues have been courting the Croatian since the season ended in May and have already seen two bids of £22 million and £27 million rebuffed by the Spurs board.
Harry Redknapp has hinted that the club may be willing to cash in on the wantaway midfielder, but the official line coming out of White Hart Lane is that the 25-year-old is not for sale.
The Portuguese tactician, however, is remaining coy on Modric amid reports that a bid in excess of £30 million will be offered before the close of the transfer window.
“We have approached Tottenham before regarding the player,” he said.
“I don't know if it is viable or not and to what extent we can go regarding his price because we are speaking about a high amount and nothing else basically. End of story.
“Whatever comes from Harry's mind is his own opinion about the situation.
“I just have to study the rest of the market and hopefully find a solution for my team.”
The former FC Porto boss revealed last week that he is still in the market for two more midfielders and has been linked with Valencia’s Juan Mata, FC Porto's Joao Moutinho and Liverpool's Raul Meireles.
However, the 33-year-old is keeping his cards close to his chest when it comes to potential targets, while admitting the club are keeping their options open ahead of the transfer deadline.
“That's a lot,” he added.
“Why don't we dwell on the names that already have been spoken about and never came?
“Neymar, [Samir] Nasri - how many names have been linked with Chelsea
in the past and they didn't come?
“In our operations, in whatever we do or not in the market, we try to keep it as silent as possible.
“We have been studying all kinds of options."
