1 City manager faces huge task at the Camp Nou
Despite Barcelona's dominance of possession and territory Manuel Pellegrini, would have been more satisfied than his counterpart Gerardo Martino at half-time. The Barcelona coach ended the opening period stamping his feet in fury inside the technical area as he watched Jesús Navas find some rare space down the right to send in a cross for Álvaro Negredo. Yet City's optimism would fade as the second half unfolded, Martín Demichelis was sent off and Barcelona scored twice. Of his approach to this game, Pellegrini had said: "I do not believe in talking about tactics, we play a certain way and we do it to our best capability then we are very hard to beat. If you want to be the best you have to beat the best and we have shown our quality already this season by winning away at Bayern Munich." Now, though, Pellegrini must mastermind an arguably harder task at Camp Nou in three weeks' time.
2 David Silva sparkles only sporadically
After 20 minutes the player Pellegrini considers the X factor in his side slipped in Negredo for City's first clear chance but the lone striker failed to accept the opportunity. While this was a rare moment of Silva's magic the foothold the side established as the first half wore on came about as he began to prompt team-mates in and around Barcelona's area. Of how City could knock Lionel Messi and company out of the competition, Silva had said: "The important thing is that we must score at the Etihad and take an advantage back to Camp Nou because if we do this, we will increase our possibilities of going through to the quarter-finals." Yet after Messi's penalty – and Demichelis's sending off – Silva may regret voicing these words as he became an ever more peripheral figure as City engaged in damage limitation.
3 Yaya Touré struggles to make an impact
The question was which Touré would turn up – the languid uninterested player or the game-running unstoppable force on display in the weekend's FA Cup win over Chelsea? In the first half there was one flash of the player who can terrorise any opposition. After a give-and-return with David Silva, Touré moved forward to beat three players and threaten to walk the ball past Victor Valdés. Yet as the contest went on and Barça began making inroads in City's half the issue for Touré was whether he could force his way into the contest to help destroy this dominance. Evidence came in the harrying of Andrés Iniesta inside the City area, forcing the midfielder to shoot hurriedly, and in the yellow card he drew for yanking Xavi back.
4 Cesc Fábregas the driving force for Barcelona
This was a night when Manchester United were able to appreciate what they would have acquired if the former Arsenal captain had joined them last summer. Fábregas illustrated why he will become the heatbeat of the Barcelona team when Xavi retires. Whether popping up on the left, right, or in the centre, outside the City area or dropping deep to collect the ball, the Spaniard was his side's fount of energy and invention. There was also a tangle with Touré near the goal that showed Fábregas's spiky side as he told the former Barcelona player to get to his feet. One surge-and-dribble past a string of blue shirts took the breath away. Of United's interest, Fábregas had said: "I do follow the Premier League a lot and it's always flattering when a club like that talks very well about you and you can see they want you." His performance showed precisely why this was the case.
5 Martín Demichelis is City's achilles heel
When the team sheet was issued the headline selection appeared to be Aleksandar Kolarov's inclusion at the expense of Samir Nasri in a move that appeared to indicate Pellegrini had learned from the 3-1 home defeat by Bayern Munich in the group stage. The idea was that the Serb would bring more solidity ahead of Gaël Clichy on the left side. Yet Kolarov was largely reduced to a spectator in the role as the visitors attacked centrally or along the opposite flank. In fact, as in the 1-0 Premier League defeat by Chelsea, it was Demichelis who proved the weak link to raise further questions of why Pellegrini has been favouring him over Joleon Lescott in central defence. The Argentinian consistently gave away possession and when Iniesta played in Messi he looked all of his 33 years, bringing down his compatriot to concede a controversial penalty and get himself sent off.