The head coach has previously indicated that the rookie power forward, who missed the end of the last college season with a torn ACL, will not play this season.
Brown told the Delaware County Daily Times: "You bucket him up into, 'Is it a total rebuild?' and I think Nerlens is a total rebuild.
"You do stuff with Evan [Turner]'s footwork, which we've done. You do stuff with release points and exaggerate follow-throughs with Tony Wroten, because everything is a hot stove. Everything is tweakable. I think Nerlens is a total rebuild.
"We're really trying to go back to a lot of one-handed shooting. I can sense he is shooting with two hands behind my back. What happens is, the off hand comes in and the elbows start coming out. When he goes one-handed, he gets the elbow under it and he gets a good-looking shot. He can't get his guide hand on the ball. It just sends it all over the place."
The 19-year-old was the sixth overall pick in this year's Draft.