No.
Unlikely, but anything can happen, that's why they fight. I didn't expect Donaire to lose to a guy with 11 pro fights and it happened, so you have to give Russel the benefit of the doubt until the final bell rings and the scores are in. Clearly Mares would be the favorite and Russel the underdog.
Hahahahah Mares would kill Russell today Russell is not ready for this type of fighter right now Russell needs a lot more seasoning before he is ready for this type of fighter.
Mares by knockout if they fought today. Ask this again in a few years though...
Not a chance
No chance
If they fought, who would win?