The Portuguese has come under heavy fire after a disastrous run of results that culminated in Wednesday’s 3-1 Champions League defeat to Napoli.
There are also strong suggestions that a number of senior players do not believe their 34-year-old manager is the right man to take the club forward, although Villas-Boas insists he is already planning for next season.
But Ivanovic, who joined the club from Lokomotiv Moscow in 2008, believes Frank Lampard and Ashley Cole, who are rumoured to be among those with doubts, must put the team before personal interests.
And the 27-year-old insists Chelsea can turn their season around after going on a run of just four wins from 14 games in all competitions.
“For me this is the hardest moment of my four years here,” said the Russian, deep in the bowels of the filthy yet wonderfully atmospheric Stadio San Paolo.
“We haven’t won a lot of games and our confidence is not in the best way. We must do all we can do to do well, we must keep going and be positive.
“This is the way to pass this critical period. If everybody works right I think we can get a reward for our hard work.
“Do players have to put the team first ahead of their own considerations? Yes. This is one of the most important moments and we all know that.
“Of course if there are some players who don’t play you can see they are big professionals and they are doing their bit for the team. We have to be together with each other and it can help us pass this moment.
“All the players are behind the manager. These things are always coming out when you’re losing. What we can all do together is still believe and try to do the right things.
“I don’t know what the manager is saying [about it], but it is more about what is happening with Chelsea. That is more important than the relationship between the manager and players.
“Chelsea has to be in front of everybody to get the result. The manager is doing his job by deciding who plays and we as players have to do our job. I think every player thinks like that and tries to make things better from this position because we have a lot of things wrong, but this is Chelsea and we have to do these things.”
Yet the speculation over Villas-Boas will not go away. Cole is understood to have been particularly vocal when told he was dropped for the clash in Naples, although the full-back came on in the 11th minute due to Jose Bosingwa’s hamstring injury. By dropping Cole, Lampard and Michael Essien, Villas-Boas was making a statement, but one which backfired horribly.
“I can’t say who will stay, but all these things are interesting for you [the press],” said Ivanovic when asked if the manager had told his players he has their backing.
“For us we have to be more focused on our jobs. We don’t have to care about these things [speculation]. I think it’s a hard position, very difficult. For us it’s very important to staytogether.“Our team, our squad is not doing what is expected of us. This is a fact.” Indeed they are not. What is so striking about Chelsea now is their lack of certainty in defence — Jose Mourinho would never have countenanced a player as error-prone as David Luiz, for example — and their lack of speed going forward.
The swift counter-attack and the rapier thrusts of the Chelsea team that Mourinho built have now been replaced by ponderous, lethargic movement and a lack of energy.
Chelsea simply had no match for Ezequiel Lavezzi and Edinson Cavani on Tuesday night, and if Roman Abramovich had any sense he would ensure purchasing one or both of that pairing was as important to him as ensuring the future of his manager.
But when Chelsea defend as they did on Tuesday night, they have no chance. It is almost certain that Napoli will score in the return. If Gary Cahill and Luiz are the centre-back pairing again trouble awaits, both for the manager and his players.