Speaking as a 26 year old that injured his back ONCE, recuperated to good shape, then aggravated it with eight straight years of lifting nearly 1000 tires a day by hand (except on weekends), I can firmly say that Turner will be fine early in his career, but he will degenerate as he gets older ala Tracy McGrady.
Hell, he may have the same career arc as McGrady. Everything will be fine for about eight years, then he becomes scapegoat material.
I hope not, but I have a very strong gut feeling. Back problems NEVER go away.