Cahill was spotted at Chelsea’s victory over Sunderland at Stamford Bridge, which the Blues narrowly won 1-0 due to a Frank Lampard goal, whilst his move is expected to be confirmed within the next 24 hours.
Following intense talks which finally produced a resolution, the England international underwent a medical on Friday after travelling to London, and Villas-Boas has kept no secret of his eagerness to work with the player.
The Portuguese boss is convinced that Cahill has all of the vital elements that are needed to be a success at the Bridge.
“He adds to a very solid back four that we have,” Villas-Boas told Sky Sports.
“Gary is a player of tremendous technical qualities for a central defender, which is what we like, because of our possession when we build up from the back.
“He has good stamina and a good sense of anticipation, which were the characteristics we were looking for and we managed to get an England international.”