Cahill surprisingly remained at the Reebok Stadium last summer despite interest from Chelsea, Arsenal and Tottenham, although the England defender admitted that he couldn’t pass up the opportunity to play for a club involved in the Champions League.
It is also just a few months until Euro 2012 and a central defensive partnership with John Terry at club level could pave the way for Fabio Capello selecting the pair during the summer tournament.
“Chelsea is a massive club, it is a club that looks to win trophies season in, season out and it is a big opportunity for me to be a part of that,” he told the Blues’ official website, www.chelseafc.com.
“Opportunities like this, you can’t turn down.”
Cahill will be paid £80,000 per week at Chelsea, something that represents a huge increase on his previous salary at Bolton and Andre Villas-Boas is delighted that the central defender adds competition for places.
Villas-Boas said: “He has good technical abilities which is important in the way we want to play and to implement our philosophy.
“Competition will be tight for him but we brought him in to become better as a team.”