I think the Tigers will win the division easily. They are projected score over 40 more runs than any other team in the division and have arguably the best starting rotation. So, I don't see how they don't win the division by 5 games or more.
I have little confidence he will play more than a few weeks. It seems like he could be done for the year (or his career) if he sustains any kind of trauma to his head at all.