Barcelona are piling the pressure on Chelsea and pushing hard for a tie-winning goal. They're not going through as it stands, so there's no question about what they're trying to do or what they have to do. They need to attack and they need a goal. So Pep Guardiola has brought on ... Seydou Keita?
Keita has replaced Cesc Fabregas in the 74th minute, for reasons unknown. This is not to disrespect Keita, who is an excellent player, but he's hardly a creator or a goal-scorer. If Guardiola made this sub in a game where Barcelona were level or leading, it would be characterized as a defensive substitution. It's an interesting and curious sub, to say the least.
We'll have live coverage throughout the game in our Barcelona vs. Chelsea, 2012 UEFA Champions League StoryStream. For more on the two teams, head over to Chelsea FC blog We Ain't Got No History and FC Barcelona blog Barca Blaugranes.