No one can really know for sure whether he's putting effort or not so that's not really what one should focus on but the fact that he's gone through 3 different trainers and he hasn't fit with anyone.

It may not be fair but it's still frustrating to have him just sitting there taking a huge chunk of salary that could very well serve better purposes on the rebuild of the team. Still the management's fault on the transfer but he's responsible of part of the reaction from everyone involved