The Blues' are in real danger of finishing a campaign without a trophy for only the second time since the Roman Abramovich revolution first saw them crowned Barclays Premier League champions in 2005.
On the other occasion, 2008, Avram Grant was sacked as manager, giving Ancelotti genuine cause for concern about his own fate.
Under pressure: Despite the starting the season with formidable reputations, Chelsea duo Carlo Ancelotti and Fernando Torres have come in for heavy criticism
But ahead of Saturday's Premier League game against Wigan, captain Terry gave the Italian his total backing.
'There's been no talk about changing him as far as I'm aware,' he said. 'The players are 100 per cent behind him.'
The same applies to Torres, who has been branded a ?50million flop after failing to score since his move from Liverpool.
The Spaniard's now-infamous drought continued in Wednesday night's 1-0 Champions League quarter-final first-leg defeat to Manchester United.
Terry said: 'It's just a case of getting that first goal, getting that off your shoulders, and then you can move on.
Desperate measures: Torres is yet to score for Chelsea and caused uproar after diving in the Champions League match with Manchester United
'It must be hard as well, people carrying on talking about it. It must be a big weight to carry as well with the fee that he came for.
'But he knows he's good enough to play, the players certainly know he's good enough, and he's got our full support.'
Torres could find himself back on the bench tomorrow if Ancelotti persists with his striker rotation policy.
Head boy: Terry is confident Chelsea can overturn the first-leg deficit
Terry said: 'Obviously, there's big competition up front and, with guys like Didier (Drogba) and Nico (Anelka), big rivalry. But, at the same time, they get on brilliantly on and off the field. And I think everyone wants to help him, help him settle in and get that first goal.'
Chelsea are close to surrendering their Premier League title having slipped 11 points behind United, albeit with a game in hand.
They must also make history to reach the Champions League semi-finals on Tuesday night, with United having never lost a European tie after winning the first leg away from home.
Wednesday's Stamford Bridge showdown saw Chelsea denied what appeared a clear-cut stoppage-time penalty, the latest in a long line of calls to have gone against them in Europe since Abramovich bought the club eight years ago.
The decision convinced Terry that there is something more than footballing ability which is conspiring against the Blues realising their dream.
'I was saying to the lads afterwards that it's us versus everyone,' Terry said. 'I think that's clear to see over the last few years. Only we can change that on the football field and expect nothing from anyone.
'Nothing gets given to you on a plate and it certainly won't be in this competition.'
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