The English champions were outplayed at home for the second season in a row at this stage of the competition three weeks ago and could have been even further behind travelling to the Catalan capital had Joe Hart not saved a Lionel Messi penalty in stoppage time at the Etihad.
Both sides also come into the game at the Camp Nou in contrasting form domestically
City's title challenge appears all but over after a shock 1-0 defeat at relegation threatened Burnley on Saturday, whilst Barca have soared to the top of La Liga in recent weeks on a run of 16 victories in their last 17 games.
Yet, City boss Manuel Pellegrini is insistent that his job is not on the line should elimination at the Camp Nou all but seal a trophyless season.
"I have no sense whatsoever that my job's at risk," the Chilean told The Guardian.
"The Champions League is very important but it can't distort everything."
Pellegrini was criticised by many for his over-eager attacking intent in the first leg, which allowed Barca's star front three of Messi, Luis Suarez and Neymar to prosper.
However, he believes that philosophy is what still gives them a chance despite the daunting prospect of having to win at the Camp Nou.
"The starting point is that it is possible to go to Barcelona and win
We have to have that mentality, our mentality.
"Our identity is to have a big-team mentality, to go to win
And now losing 2-1, we have to attack."
By contrast, Barcelona now have a treble in their sights with a potentially decisive La Liga clash with eternal rivals Real Madrid to come on Sunday and a Copa del Rey final against Athletic Bilbao to look forward to at the end of the campaign.
The backbone of the upturn in form from Luis Enrique's men has been Messi's incredible form as the Argentine took his tally for the season to 43 goals in just 39 games with a double against Eibar at the weekend.
However, Suarez has also begun to make his presence felt after a club record move from Liverpool in the summer as last season's Premier League Player of the Year has struck six times in his last five games, including both his side's goals in the first leg.
"It is pleasing to help the team with important goals in a Champions League knockout game and of course to return to England and beat a team you're always motivated to face," Suarez told Uefa.com.
"Players like me get inspired when fans boo them - it helps motivate you a bit more."
Barca will be without the injured Sergio Busquets, so Jeremy Mathieu is expected to deputise in central defence with Javier Mascherano moving into midfield.
Gael Clichy is City's only absentee, the French defender is suspended after being sent-off in the first leg.
Source : AFP
Source: AFP