Previously against Chelsea, when Fernandinho was replaced by the barely moving pony-tailed figure of Martin Demichelis, Manchester City suffered as Chelsea's quick moving quartet tore through the field in their counter-attacks. Now at his more comfortable center back position against Barcelona, Demichelis was still the weakest link in an otherwise fairly well-constructed Manchester City team. Pellegrini's choice to use only one striker in Negredo, along with Kolarov sitting in front of Clichy on the left wing in the packed five-man midfield closed down on the available space for Barcelona to use in the midfield. City's disciplined and deep defending was stifling opportunities for the visiting Spaniards, however also led to their stuttering offense never really able to retain possession. Demichelis' sending off was a liberating of the shackles, as Manchester City was never truly dangerous until the Argentinean defender mixed everything up with his late tackle on Messi in the 53rd minute.
Messi himself put away the penalty, and a ten man Manchester City began to shine without the presence of Demichelis. They lost that reserved fear of the blaugrana which held them back in the first half, and began to play with a hint of the recklessness which previously belonged to the man who got himself sent off. David Silva came close with a well-created volley, however Barcelona continued to dominate possession and continuously found ways to cut in behind the City defence. In the final minutes Dani Alves combined in a passing triangle with Neymar, darting past the home side's defence to slide the second goal in through Hart's legs.
With this fairly comprehensive home loss, it's difficult to consider that Pellegrini's Manchester City has resigned itself to being knocked out of the tournament. Despite a return leg victory being a monumental task for City, the side showed itself to have the mettle and intensity to compete with Barcelona for an entire match, even with only ten men. If Pellegrini can put aside whatever strange preference he might have for Demichelis (whether he be playing in or out of position), and instead start using the various players available to him (Lescott, Javi Garcia, and many more), there's the true possibility of his team mounting a comeback.
The Chilean manager's tactics weren't off the mark, rather, they were just brought down by a single clumsy Argentine defender. Pellegrini finally got his formation set up without any gaps, and in the second leg without Demichelis, perhaps along with Aguero fit and back in the side, Manchester City is suddenly looking much competitive than some might expect.