He was pitching against a little league team. Let's wait until he's facing legitimate hitters before concluding to jumptions.
He has pitched four games so far, pitched at least 6 innings in each, and allowed 4, 3, 3, 0 runs. He also pitched at least six innings and allowed three runs or fewer in six of his last eight starts last year. In the two that he didn't, he pitched eight innings allowing four and six innings allowing five. And in 2014 he had 21 starts of six innings and three runs or less.
But clearly the eleven starts in 2015 where he allowed more than three runs are more important.
Which is to say no, it's not jumping to conclusions to think Porcello is a guy we can rely on to get us through the first six innings and keep us in the game. It won't happen every game, but it will happen in most of them. If Price pulls his head out of his ass and any two of Buchholz. Wright, Rodriguez, Henry, Johnson, Elias, and Kelly can be competent, this is going to be a very good team.