In an effort to contribute to the theory that he's run out of ideas for what to do with his team, Pep Guardiola has substituted off Isaac Cuenca for Christian Tello in the 68th minute. If you're unfamiliar with the two players, Tello is basically just a worse version of Cuenca. Because Barcelona haven't had to chase the ball much at all and Tello started El Clásico at the weekend, it's unlikely that he actually has significantly fresher legs.
Chelsea are actually looking OK while breaking out on the counter at the moment, and they don't look terribly bothered in defense. The longer this game has gone on since the Lionel Messi penalty miss, Chelsea have looked more and more like the better team, even with 10 men. It's pretty remarkable.
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.