People get past Marchisio too easily, and to think some people wanted him to be paird with Aquilani. He really isn't much of a defensive player, the only thing that makes people have that perception, is because of his work rate and stamina.
Yaya dominated him today, but to be honest, anyone who has watched City this season knows that Yaya has been a very good signing for them thus far and has dominated almost every midfield in front of him this season, including Chelsea's midfield. Top signing.