The Blues have already seen two bids - the second of ?27million - rejected by Spurs, who insist that they are not prepared to sell the Croatia international.
Modric has made no secret of his desire to join the Stamford Bridge side and it is understood he has handed in a written transfer request to Tottenham.
Villas-Boas, who was speaking in the wake of Chelsea's 1-0 pre-season friendly victory over Portsmouth, also confirmed he is considering a move for West Ham's Scott Parker.
But the Portuguese tactician claimed the West London side are already considering alternative options should they miss out on playmaker Modric and fellow midfielder Parker.
Villas-Boas said: "I prefer not to comment, but you know what the situation is, it's public.
"We understand the position that the club (Spurs) has taken, so at the moment we are scanning the market for everything, not just those two players (Modric and Parker).
"It is one of the positions we are looking to strengthen. It is just a question of finding the solution.
"If it happens, it happens. If it doesn't happen, it doesn't happen."
When asked whether a deal for Modric was just a matter of time, he retorted: "No, it does not depend on us.
"Spurs have a right to defend their player and property. We just have to wait.
"We respect whatever position Tottenham takes and the prices we are talking about is an incredible amount of money."
As well as a creative midfielder, Villas-Boas admitted that he would like to add a defensive midfielder to the mix after Michael Essien's injury.
The Ghana international has been ruled out for six months with a knee injury, which Villas-Boas admits came as a big blow to everybody at the club.
"Michael is a fantastic person and a fantastic individual," he said. "He was one of the people I kept in contact with for a long time after I left and I always considered him a friend and it was a pity for him to get another injury like this.
"I think it is a big blow because of what he represents and what he represents as a person.
"Six months is a lot of time and for sure bearing in mind this was already a sector we were looking to strengthen we might need to move in the market."
Spurs assistant boss Kevin Bond, meanwhile, doubts Modric handing in a transfer request will make any difference to chairman Daniel Levy.
Less than 24 hours after the Croatian playmaker told the club he wanted to leave, the 25-year-old was left out of Tottenham's pre-season opening defeat against Kaiser Chiefs because of an ankle injury.
Levy has said from the beginning that the influential midfielder would not be going anywhere and has already rejected a bid from Chelsea, reported to be in the region of ?22million.
Following the friendly in South Africa, Bond said it was a matter that Modric and Levy needed to sort out between them and crucially before the new Premier League campaign started.
"If he's handed in a transfer request, he's handed in a transfer request," said Bond. "The chairman will do what he wants to do with that but his line so far has been pretty clear - he won't allow Luka to leave the club.
"He wants to keep all our best players so I'm not sure that makes any difference to our situation at the moment.
"It's a situation that Luka Modric needs to clear up with the chairman and we need the season to get underway with everybody pulling in the same direction, all of the players, everybody pulling in the same direction.
"Hopefully by the time the season gets underway and this situation gets sorted out, that's exactly what will happen."
Source: Team Talk
Source: Team Talk