The 35-year-old centre-back appeared to be ending his career-long stay with Chelsea at the end of last season, but in May he signed a new one-year deal to take him into his 22nd season in West London.
And whilst many didn’t believe he was good enough to be a starting player this season, Antonio Conte has kept faith in Terry, starting him in both of the Blues’ two Premier League games so far.
When the deal was announced there was an outpouring of praise for the club to have tied the club legend down, and Cahill believes keeping Terry at Stamford Bridge was a ‘fantastic’ move for everyone involved with Chelsea.
Speaking to talkSPORT’s Warren Haughton, Cahill said: “It’s fantastic he’s stayed for another year. It’s fantastic for everyone involved – the players feel that way, the fans feel that way and the club in general.
“So that’s a huge plus point. And for me, like I’ve always said, he’s an unbelievable player – one of the best centre-backs you’ve seen in the last 10 years in the league – and I feel the older he gets, he still brings that quality, still playing at a very high level.
“But also it’s important he’s here for players coming through, for the younger generation coming through – for every reason. He knows how this football club works; he knows what’s expected of players that player for this club. He can put an arm round the younger players – when I first came I learnt a hell of a lot from him.”
With five days of the transfer window left, Cahill and Terry remain Chelsea’s first-choice defensive partnership, despite Conte being keen to add a new centre-half to his squad.
Bids for Napoli’s Kalidou Koulibaly and Milan’s Alessio Romagnoli have been rejected, and it is expected the search for a new signing will continue right to the deadline.
One of these players arriving in the next week is sure to push Cahill out of the starting line-up, but the England international remains confident he has the ability and strength of mind to fight and retain his place in Conte’s plans.
He added: “This season I’ve just come into a totally selfish mindset in what I’m doing. Like I said, I’ve worked really hard in pre-season, and I’m in the best physical condition I’ve been in for a little while, so selfishly I’m concentrating on what I’m doing.
“If we strengthen the team that’s fantastic, if we don’t – we don’t. But I’ve been here a long time now – tomorrow could be 200 games [at Chelsea] – and I keep working and keep going.”