Keane signed a new 12-month contract over the summer, amid rumours of the veteran departing. And it's proved a canny move by the Toffees with Keane impressive standing in for the injured Jarrad Branthwaite.
Dunne told Tribalfootball.com: "He's been a really good servant for Everton, and he's always been there and been someone that they can rely on when they've needed him.
“I know I, at times, they've thought about moving on and bringing in centre-backs, and when Jarrad Branthwaite is fit, he'll probably play. But every time Michael Keane's called upon, he performs, he does well, and this season he's been part of an Everton side which is looking up rather than looking behind them all the time.
“So, I think it's a justified extension of his contract. Whether he's going to be the long-term first-choice centre-half, I'm not sure. But to have a player of that quality in and around the squad is, is very valuable for Everton.”
Meanwhile, fellow Irishman Jake O'Brien has also impressed as a makeshift fullback under manager David Moyes. Dunne says a future in his natural centre-half role is within O'Brien's grasp.
He continued: “I think he can. He's played there for Ireland for the last couple of games and done really well. I think he's naturally a centre-half just because of the size of him.
“He's more suited to that position than playing as a full-back. He's done really well. He's looked very dominant in that position at times, and there aren't many wingers who have got the better of him in that period that he's been playing there.
“I think inevitably for himself, he'll want to become a centre-back, try and get himself playing there more regularly at Everton.
“But he's not got a load of Premier League experience. So, to gain that, if that means having to play right-back for a period of time, well then so be it. I think he'll be at Everton for a long time, and I think, eventually, he will be moved back into the central area.”
Everton great for Grealish
Dunne also had a word for Jack Grealish, who is already starring for Everton after joining on-loan from Manchester City.
Like Grealish, Dunne also turned out for City and says the England midfielder is already getting close to his best form.
He said, “I think he's pretty close to his best at the moment. He's had a great start since he went to Everton.
“He's playing with a little bit more freedom than he has done over the last couple of seasons. He seems to be playing with more consistency, and he has the full trust of the manager. So, I think that's really helped him.
“If he's to continue in the same vein of form that he's in at the moment, there's no doubt that Everton will be pushing to try and sign him.
“They've already agreed on some sort of pre-transfer fee, so I think it'd be a great signing for Everton."
- Richard Dunne was speaking to Tribalfootball on behalf of Betway