hey mate,
you often see this. when a player does not like his coach. he will be glad, that he has nothing to do with this shitty match, after he got subbed out and feels confirmation of his thoughts about the coaches wrong tactics.
can you blame him ? he really does give his all and does more defending than any other attacking midfielder i know, but the coaches approach does make this team look like a complete joke. he clearly has given up on ferrara and does not even care anymore for the game, because he knows he did try to explain to ferrara what is wrong, but if ferrara does do fuck up all the time, there is nothing more diego can do.
that is obviously just my evaluation of the situation, since i was in similar situations regarding the coach.