The Portuguese boss led the Blues to the title last season, but has come under enormous pressure this season after six defeats in the first 11 matches of the Premier League campaign left the club struggling just above the relegation zone.
That dismal start has been compounded by reports that the players have staged a revolt against the manager, with the BBC claiming that a first XI player said at the weekend that he would "rather lose than win for Mourinho".
But Terry, who has been in poor form this season even on the occasions when he has started, insisted there is no way anybody said any such thing.
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"In my whole football career, I've never heard a player come out with them words," said Terry. "It's ridiculous I have to talk about it. If player said that they wouldn't get out of the dressing room...
"I can assure you now that he players are 100% behind the manager."
The skipper insisted - as Mourinho himself had - that there was no question of the manager being fired.
"It's not going to come to that. The club's shown faith. He's the best," he said. "We're going to turn it around... We will turn things around. I'm positive. The important thing is together. And we're together in that dressing room."
The defender added that it is the players who have been at fault, not the man responsible for leading them.
"He's under pressure because of how we're performing. Once we cross that white line, it's on us," he said. "Jose has been really disappointed and devastated after games. He takes it on his own shoulders. We will bounce back from this."
'We need to keep Hazard and Mourinho'
Chelsea's Belgian midfielder Eden Hazard (L) vies with Liverpool's Spanish defender Alberto Moreno
Image credit: AFP
Terry added that Eden Hazard, one of the players rumoured to be unhappy this season, would also stay put.
"Mourinho's the best manager we could have and Hazard one of best players in the world," said Terry. "We need to keep both."
Terry also admitted that his own form has been poor, strangely discussing himself in the third person as he did so.
"John Terry could be better and I need to be back up to where I was last season."
'I don't listen to Robbie Savage'
Terry also used his press conference to take aim at pundit Robbie Savage, who the Chelsea captain feels has targeted him for repeated criticism. Terry said Savage's playing career for the likes of Blackburn and Birmingham meant he would not take his opinion seriously.
I’ve come under criticism, individually, from certain players and individuals, players I’ve looked up to and played alongside. I’ve taken that on the chin: Rio, Carra, Neville, the very best I’ve come up against in the game. I take that on the chin. When others speak, maybe I don’t take it on the chin. When players have not had a career, played at a really bad level in their career ... Robbie Savage being one. He’s dug me out a couple of times. You take it as a footballer, as an individual. I’ll take it from the Rios, Carraghers and Neville. All day long. From others? Nah.
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