What does have to work on? His delivery? If they want to overhaul or tweek his delivery, that's only thing I can see. But, if they keep him there just to make sure he is healthy, that makes no sense. Of course, ask any pitching coach and you really can't successfully make many adjustments to a pitcher's mechanics during the season, that's done during instrux. I've always hated this stance, it's ridiculous. Every situation they're involved with deserves questioning rather than passive accepting. I'm glad I question everything the Cubs do and try to look at it from every angle, you learn more from the game that way.