I've said this before but the NBA should design the D-league similar to what they do in baseball. Baseball players are sent(or rather "assigned" )to the minors for rehabilitation id they are returning from an injury or work out.
It helps the players so their egos aren't crushed, and it also won't hurt their NBA stats either if they play a couple of "warm up" games in the D-league. It also helps the minor leagues too because their fans have a chance to see established stars coming to town every once and awhile.
Remember last season when Boozer missed the first month then came back on the first game had 5 points and 1 rebounds or something like that. It took him a couple of game to get back to playing form. They could have had him play a game or two in the D-league before suiting up for the Bulls.