But the evidence stares you in the face week after week.
Clverley and Giggs have, at worst, been as bad as him. Both have had games where they've played quite well. Carrick hasn't. Fletcher and Jones have played quite well in midfield. Fellaini has been ok there. Basically everyone we've tried there has done as well or better than Carrick.
I thought it was strange after the Olympiakos game when so many people seemed to think Carrick's performance was surprising in some way.
The only evidence we have of what happens when Carrick is dropped, is what happened when he was injured earlier in the season...it kicked of a run of 6 wins in a row, which mysteriously ended as soon as he came back.