I still think the best use for him is in a trade package for a star level big with some youth.
I also think if one of the top 2 or 3 big men in this draft has star level potential and the Celtics do not get the Lakers pick, trade Rozier and one of the future picks to get in position to try and draft that big man.
If this team is sold on the future around Irving, Brown, Tatum, Hayward, and Horford, there just isn't the minutes nor the starting spot that Rozier wants and is earning with his play. Try to get value out of it while it is at it's highest, before teams lose the ability keep him.
But if there is no offer that helps the team next year or in the future, keep him.