I like Kosta. He is just a blue collar type of player that does his job without much fuss. Great locker room guy and a good mentor to have on the team.
Having said that, simply from a perspective of maximizing your assets, it makes a lot of sense to trade him for a pick or another asset.
If the coaching staff is right and Papa has worked and is going to surprise us then, he will need some minutes which get freed up by trading Kosta.
It also gives us a chance to trade for a SF or better yet a first round pick from one of the better teams in 2019.