Shields might be hitting the end of the road. He is up there in age. He should hit the end of the road before Porcello. That being said, until fairly recently Shield has been the better pitcher. Comerica Park is a pretty pitcher friendly environment, and Shields pitched a lot of years in Tampa which wasn't kind to pitchers. Shields trajectory may be pointing sharply down at this point. We will see, because his new ballpark is a bit of a launching pad. Up till now, I would still pick Shields to hand the ball or Porcello. Just my opinion.