Duren is the shiny gem because of his special upside — even if he is regarded as perhaps too much of a project for coach Tom Thibodeau to give approval. “A lot of people compare him to Bam,’’ Brown told The Post from his home in East Hampton. “I spent time with Cal [Kentucky coach John Calipari] when Bam was there. Bam doesn’t shoot 3s either. Jalen is 3 inches taller than Bam. “Jalen is like when I was a head coach when he had a center and power forward in the NBA. I always teased him: I wanted him to be like [rugged former Pistons center] Ben Wallace, because he can run with anybody. He really can run. And can move his feet defensively.’’