I do think a future second rounder is selling low on McCallum. He's a smart kid, the son of a coach, and plays his heart out. McCallum was picked in the 36th in 2013 and has provided pretty good value relative to his second-round status. The Kings get a second rounder in return from the Spurs, which is likely to be in the 50s, if not #60.
Its clear that Vlade isn't quite done remaking the roster just yet.