I think he started to listen too much to what was being said and written about him.
At the moment he certainly does not look like a 100m player, however his work rate is still good and a goal or two could turn his entire season around.
As a team we have become more defensive and less creative but I don't see DCL sulking about that. We are contesting for a place in Europe, just maybe although very unlikely a place in the CL which is what he wanted at the start of the season.
It just may be he will want to leave at the end of the season and this has already been agreed with his agent
It would at least in part explain his apparent discontent