I haven't seen one.
He was being mentioned along with Allen as 1 of 2 QBs (Allen) that would be getting snaps in the spring but came down with a sports hernia right before spring camp started that seemed to keep him out for most of it. At one point in camp, CMA said that he'd be back right after spring break, but he only come back in drills, but no contact.
If he is leaving, my guess is it's because he basically knows he's behind the 8 ball as Allen and King are ahead of him with Bryson Smith coming in. Throw in McClendon and Postma and Sells is probably seeing another year of no playing time. Might as well move on now.