#4 C Walker Kessler
Walker Kessler really didn't improve much from his rookie year to his second season in the NBA. His stats stayed all about the same, though a bit down from the prior year. He went from 8.4 rebounds to 7.5 rebounds per game but that also has to factor in John Collins' arrival and the playing time and opportunities he took from Kessler. His points per game fluctuate a bit, going from 9.2 to 8.1 points per game. His blocks increased a tad, going from 2.3 to 2.4.
He largely played as well in year two as he did in year one, but that wasn't enough for Will Hardy to give him a larger role, sticking him as a bench player, getting just 23 minutes a game. Despite that, his defense never failed him. He didn't grow or establish any new aspects offensively but his defensive skillset was still more than enough to carry him to a Top 5 finish on this list.
He had a +1.3 DBPM, just slightly off from his rookie season of +1.5. He was still a very effective defender, and while his offense dipped some, he did still post an overall BPM of +0.9 and a VORP of +1.1; fifth and fourth best on the Jazz respectively.