DeMar DeRozan took to his Instagram story prior to the news that he was being traded to the Spurs for Kawhi Leonard and he made it clear he isn't happy about the trade.
DeRozan revealed that he was lied to by the Raptors and that he believes they're getting almost nothing in return.
So there's probably no chance of DeRozan ever returning to Toronto. This bridge has been thoroughly burned. And he's not wrong about being traded for nothing. Kawhi is going to jump off the Raptors ship as soon as possible.