The Stamford Bridge club are expected to strengthen their squad in the new year, as the Portuguese coach tries to make the Chelsea team his own.
The Blues have been linked with a move for Cahill of late, but this is not in the club’s plans according to Villas Boas.
“He’s a fantastic player because he plays for the English national team, a central defender of high qualities,” he told Sky Sports.
“He had a fantastic year last season for club and country. But he is not a player that we are considering.”
Cahill is in the last year of his contract and is likely to be the subject of transfer speculation when the window reopens, with Arsenal and Tottenham thought to be interested in the centre half.
Chelsea failed to sign Spurs attacking midfielder Modric during the summer, with the North London club rejecting a number of bids from their cross-city rivals for the Croatia international.
Spurs fans will have expected Chelsea to come knocking for their star player again in January, but Villas Boas states this will not be the case.
“We have Michael Essien returning and I think we have left that one for sure,” he said.
By Gareth McKnight