Off topic thought, after DL Hall, I can't picture any of our other pitchers from AA and up (still rookie eligible) that deserve to be in the top 10. Bauman, Kremer, Kevin Smith, Bradish, etc. group seem to be future middle relievers and old prospects (if 25 is consider old). However, I do hope for a John Means resurgence for one of them.
Well, its not very hard to take him from a starter and put him back in the pen.
However, they may not want to jerk him back and forth because of his injury history. Its a totally different way of preparing your arm and throwing when you go in short stints vs being a starter.