Roberto Mancini has told his Champions League flops they owe him "three big performances" ahead of Manchester City's do-or-die clash with Ajax tomorrow night.

Mancini has already admitted City need "a miracle" to salvage their Group D campaign after taking just one point from their opening three games.

The Italian reiterated after Saturday's bore draw at West Ham that the Barclays Premier League champions were "not ready" to be crowned kings of Europe.

But he insisted he would not tolerate them crashing out of the Champions League with a whimper for a second successive season.

"You should play 100 per cent every game. It's normal, no?" he said. "We have three games. We have to think only about Ajax at this moment and we will see what happens."

Asked if his side owed him a big performance on Tuesday, Mancini replied: "I think three big performances!"

"I don't think that we are ready to win the Champions League" - Roberto Mancini

Indeed, the City boss revealed he would demand three improbable victories from his side against Ajax, Real Madrid and Borussia Dortmund, which would see them complete a remarkable comeback to qualify.

But he added: "I don't think that we are ready to win the Champions League. If we say this, we are not honest.

"We are a good team. We are not ready like the other teams."

Mancini bristled when it was pointed out Chelsea won the Champions League last season despite finishing sixth in the Premier League, 25 points adrift of City.

"But Chelsea for how many years tried to win the Champions League?" he said.

"Chelsea were probably the best team in Europe for 10 years and they won the Champions League after 10 years, probably when they didn't deserve it.

"Probably, they deserved to win the Champions League three or four years before.

"If we are very good, we are fantastic, we win the next three games, everything can happen.

"But, before, the way is very long."

Mancini, who has never got to grips with the Champions League, also denied his side had a mental block when it came to Europe.

He said: "No, no, no. The pitch is the same, the players are the same, the referees.

"It's not this. We need to improve, we need to play better, we need to score when we have the chance. Easy."

Easy was the perfect way to describe some of the opportunities squandered by City yesterday as they failed to score for the first time in almost seven months.

Mario Balotelli was the culprit in chief as his wait for a first league goal for even longer went on.

He may have lost his scoring touch but not his penchant for petulance, as shown to his response to being hauled off.

Mancini had no sympathy for the 22-year-old, insisting a "top player" would have scored last night.

"He should be disappointed about this - not because he left the pitch in the last 25 minutes," he said.

"Not one player is happy when he leaves the pitch.

"But, if Mario scores, he probably stays on the pitch, like every other striker. It's normal.

"I'm the manager, I decide that I need to change something during the game."

Mancini defended his decision to start with Balotelli, Carlos Tevez and Edin Dzeko in the same attack for the first time, despite his latest piece of tactical tinkering going awry.

He admitted he had rested Sergio Aguero partly with Tuesday's game in mind, saying: "He was so tired."

Saturday's result saw City blow the chance to join Manchester United at the top of the Premier League after Chelsea's slip-up at Swansea.

Their performances are a far cry from a year ago, when they were blowing away even their fiercest rivals.

Asked if teams were trying harder against his side now they were champions, Mancini said: "When a team plays against a champion like us, they try to play better.

"Maybe they put more than 100%. But this is normal. This is football.

"For this reason, the second year is always more difficult."

Injuries have not helped and yesterday saw James Milner join the crocked list, with Joleon Lescott also all but ruled out of Tuesday's game.

"We have a lot of players injured at this moment," Mancini said.

"But now we play the next game and definitely we will see what happens.

"The season is long."