I think the main reason for him perfoming poorly in the second half of the season is a mental issue, something that is brought on by the quality of the opponents we face (at least this season anyway). For the first half of the season our strongest 11 had him in midfield with Iniesta on the left and because of the quality of the players we have, we swept aside most opponents relatively easy. However, we had that two week period in the second half of this season where we played Madrid a couple times and had the first leg against Milan where that formation did not work and it became clear that his role in the team was not working against top class opposition. It is now obvious that he does not fit into our best 11 against the strongest opposition and this is causing his game to suffer against weaker opposition as well now. He got his dream move back to the club he loves and it is not going as he would have hoped and this pressure is taking its toll on him and his performances. As I have said before, once Xavi has retired and he becomes a part of the strongest 11 and he is trusted more he will hopefully excel and overcome this. It is worrying for now, but there is no doubt that he has the talent to overcome this issue.