I could see a scenario where Stefanski is made interim GM and Casey is kept on for this upcoming season. During that time Casey is told to focus on defense and Stefanski is given the mandate to accumulate as many assets and as much flexibility as possible from the core of DeRozan/Lowry/Gay/Bargnani.
2014-15 would then give a new GM a clean slate with a LOT of flexibility.
Another rebuild many will say? Well, it has been on going for 14 of 18 years, what is another 1 or 2 if done with leadership possessing the patience to stick to an actual plan?