The problem with Howard is that his mindset is on what he used to be able to do and right now he just isn't at that level. He needs to play within himself and not chuck up shots that have little chance of going in. If he can do that and get himself focused the way Carroll does, then he should be ok. I don't know what the coaches are telling him, but if I were the coach, I'd say stop taking those dumb shots and look more to create for your teammates. And the first time he chucked, I'd yank him.
Yaysus, he is the experienced vet and should know that already. If he has to be told that then his experience has gained him no wisdom so his experience is not valuable. Give the minutes to Burks so he can get some experience he may put to good use in the future.