What I would do during the next off season is add a "Short Season A" team. A lot of times in my game, the AI, (minor league managers) will say a guy might be ready for "Short Season A", but apparently doesn't think he's ready for my regular "A" team. What you may have here is a manager who is conflicted because he doesn't have the option to send a guy to a short season A team. So he sends him to your A team then says "Crap, he's not ready for our A team, better send him back to rookie ball.
I'm only guessing, but I think it's a good guess.
