Don't see the need for D-League..I can buy that it could help him learn the system, but this dude isn't a rookie, hes an experienced played from a respectable league, I don't see the point of sending him down..
His experience in the NBA should come in the form of real compe ion where he has to defend the pick&roll against rotation players, get accustomed to the 3 seconds rule, defensive rotations against NBA systems and athletes, etc..
Preseason, garbage time and November/December games against the Phillys, New Yorks and Lakers of the league should suffice for initial experience..