The report comes from Marc Stein of ESPN, through this tweet:
This is an interesting move. Tony Snell had multiple opportunities over the years to seize a spot in the rotation and never managed to take advantage of the opportunity. Still, despite his ever receding role, it never quite seemed like Snell would be the first man up to be moved.
The return piece in the trade proves to be a bit more interesting. The Bulls just traded away a former Rookie of the Year point guard and just a few months later they are looking to add another one in Michael Carter-Williams.