to be honest, it doesnt really matter if you keep him or trade him.
you wont be able to get more than a few thousand on him if you trade because of his age and his stats. so comparing to your other players if hes good then keep, if not, then trade. if he had better inside skills and free throw then i would say keep for the hell of it, but otherwise, theres plenty of guys with his stats that you can purchase for $4000