The Croatia playmaker has made it clear he wants to move to Stamford Bridge, but Spurs have turned down bids of ?22m and ?27m for the 25-year-old star.
Blues manager Andre Villas-Boas admits he is struggling with numbers in midfield but his chairman has revealed he is unsure whether the move will ever happen.
Wantaway: Spurs playmaker Luka Modric (right) hopes to join Chelsea
Buck said: 'Most clubs don't want to talk about players they are interested in but the Modric situation became public.
'We did make an offer, it was rejected and I don't know if it will go any further. We will have to see.
'Andre didn't give us a shopping list but he did tell us where he thought we could improve.'
Tottenham manager Harry Redknapp and chairman Daniel Levy are split over whether to let Modric join Chelsea.
Italian job: Harry Redknapp wants to bring in a striker such as Giuseppe Rossi
Redknapp is prepared to let the ?35m-rated midfielder fulfil his Champions League dream so he can bring in up to three top strikers, such as Giuseppe Rossi of Villarreal, Athletic Bilbao's Fernando Llorente or Manchester City's Emmanuel Adebayor on loan.
Levy wants to finance new signings by selling other players and hopes to complete a ?20m deal for Peter Crouch and Wilson Palacios to join Stoke.
Modric has admitted he is still waiting to hear whether Tottenham will accept an offer and allow him to move across London.
Stalemate: Chelsea were held to a 0-0 draw by Stoke on Sunday
He said: 'I said a lot of things before and still everything is the same at the moment. I will see - I'm still waiting.'
Buck also insisted that winning the Champions League is not the be all and end all of Chelsea's season in Roman Abramovich's eyes.
He added: 'I have never heard Roman say the Champions League is a Holy Grail.
'The only thing I have heard him say is that he wants to win the next game.
'Having said that, we haven't won the Champions League so it would be great to win it.'?
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Source: Daily Mail
Source: Daily Mail