City head to the Nou Camp on Wednesday trailing 2-0 after the first leg of their Champions League last-16 tie against the Catalan giants.
Most pundits have written off their chances of reaching the quarter-finals and the daunting task is made all the more difficult by the touchline ban affecting Pellegrini.
The Chilean must watch from the stands, and have no contact with his players or coaching staff before or during the match, as punishment for controversial comments about the referee following the first leg.
Pellegrini has had other matters to worry about since then in sustaining a Barclays Premier League title challenge, the Capital One Cup final and, this weekend, an FA Cup quarter-final against Wigan.
But attention will soon switch to the Nou Camp and the challenge of engineering an unlikely turnaround.
Pellegrini said: "I am looking at every competition with the same importance.
"On Sunday we have to play in the FA Cup, so we are thinking about the FA Cup.
"But when we finish that we will try to make a good match against Barcelona to try to have our revenge and continue in the Champions League."
City's progress to the last 16 represents improvement after failing to get beyond the group stage in the past two seasons.
Yet there was no hiding the disappointment last month as Barcelona outmanoeuvred them tactically.
City deviated from their usual 4-4-2 formation by bulking up the midfield to absorb pressure.
It worked to a large extent, and chances were created on the break, but Barcelona controlled possession and played a patient game.
The game turned in an instant Lionel Messi found a gap and was brought down by Martin Demichelis, who was sent off, for a penalty.
Pellegrini's rant at Swedish referee Jonas Eriksson stemmed from that incident, as he believed the offence was outside the box, but he could not hide the fact his team were caught out.
For much of the season Pellegrini has stuck to his preferred system and attacking principles, and that is likely to be the best way to serve his team this week.
The Chilean, whose side are buoyed by last week's League Cup success, said: "Not all the teams play exactly the same all the time, every time.
"Maybe it is not easy for us to play against different teams in the way we always want to do it but it is very important to try to continue the way we want to do it.
"The final of the Capital One Cup was one example of that.
"We were not on our best day but we tried to play in the way we always do, but with patience. In the end we scored goals.
"We are always trying to improve in defending and attacking.
"Maybe in two or three matches at the beginning we didn't defend well, against Cardiff, Aston Villa and Arsenal, when we scored six.
"But we are always trying to work to improve in all senses.
"In this part of the season I think we are defending well, even though we are not scoring as many goals."