Callan thought he was too good for the nix when he left the last time and went to Europe and regressed terribly. I don't think he has made it back to the level he was at when he left last time, he was like a right sided Libby in the last couple months of that season. I'm not at all upset he's leaving, particularly as it sounds like he was trying to extract every last dollar out of the Nix. He should have learned by now that it is critical early in your career to be playing regularly and developing, and once you've made it, you can then name your price and you will always have options. He needs better management/advisors. Good luck to him but I doubt he will be the player he could have been
Edit: from a quick glance at wikipedia he maybe made a couple of appearances under Rudan but it wasn't until the latter half of Talay's first season that he made the RB spot his own ahead of Fenton and payne. And that was a back 4