Again, no one is saying that he is a 6.0 ERA pitcher, because he is not. He is a 4.4 ERA career pitcher who has increased dramatically his HR/FB% since 2014 and looks like 2013 actually (which worries me), but that's not the point. The point is that his recent performance, (ST and this first start is not encouraging), in order to think that he is going to improve what he did in 2015. Some still think that his 2014 numbers or even more is his potential, I still think that it was a fluke year. Take away his best and worst years and you will figure out what Porcello really is.
We'll see though.