Toronto Trades: Andrea Bargnani
OKC Trades: Jeff Green, DJ White
Jeff Green is OKC's biggest liability defensively because he is playing out of position. Bargnani is more suited to defending opposing centres/power forwards in the west (such as Gasol, Bynum, the other Gasol, Cousins, Haywood, etc) and in a strong defensive system like OKC's, he can grow as a help defender as well. Bargnani would also be a strong complementary offensive piece, probably playing 3rd fiddle to Durant+Westbrook.
In Toronto, Jeff Green slides in as the starting small forward, where he becomes much more adequate defensively. DJ White provides depth to a centre position that would become wide open with Bargnani's departure.