I'm not denying that Cahill did well last season..but that was more to do with the way Mourinho set up the team.. When we sit back, Cahill generally performs well..but when he is asked to play with a bit more risk/higher defensive line, he seems less secure and panicked as a defender. I'm just trying to say that Zouma has alot to learn and Cahill may not be the right player to use in a higher defensive line...signing a quality CB for next season wouldn't be a bad option for Chelsea...