Yaya is the power in the midfield, I still remember that game against ManU in semis back in '08 with Rijkaard. He dominated the whole match, definetly his best game i can recall. For some reason, Pep prefers Busquets, I don't know why, but it would be a big mistake selling him. Yes, his form was not really good this season, but it was simply becuase he didn't have playing time, that was also the case last season, but as Pep gave him more and more playing time he became one of the key ingredients in our last years treble success. Buying Mascherano for anything more than 25mil. would be a terrible signing policy for me.