The former Bolton defender joined the London club 14 months ago for a fee around €8.5 million, and this season has been a key player under Rafa Benitez, making 42 appearances out of a possible 52.
The Englishman told The Telegraph about his time at the club.
“I feel like I have been here about five years!” he reflected. “A lot has happened in that period of time.
“It has been a bit crazy. In the period I have been here we won the FA Cup, won the Champions League, which is the best competition you can ever go into, and lost a couple of finals as well. So it has been crazy.
“The main thing is that I am playing in a lot of the big games, I am playing more regularly now, but we have got the luxury of four centre-backs now so we can chop and change. I think maybe I proved when I first came that I could play in the Champions League, because we went on and won it, and I played the games in there. Playing with England has helped me as well.
“You come here from a smaller club and people wonder, can he play here, can he do this? And you always feel like you are trying to prove to people all the time. For me now it is just trying to prove that I can maintain a starting place at Chelsea.”
With the fans venting their anger towards the interim manager, Cahill admits that Benitez has a tough job at Stamford Bridge.
He added: “I think we know a lot more about what he expects of us now. He is really thorough with the way he wants to play and his tactics. But it is difficult because of the amount of games we are playing.“I can’t tell you how many times we have everybody out for a full session. We have games, half the lads who didn’t play have to train, the other half can’t, so to get the full group together on the training pitch doesn’t happen very often and that is very difficult for the manager.”
Cahill has also hailed the ability of his team-mates, especially Eden Hazard and Oscar, who joined the club in the summer for a combined fee of around €70 million.
Cahill continued: “Eden [Hazard], Oscar, they are fantastic players. These lads are the future of Chelsea. They are phenomenal footballers. But it takes a little time to adjust to this league. So I don’t think we are a million miles away. We have just slipped up a couple of times in situations where you would not expect us to.”