Sanchez is a bottom tier quarterback to this point in his career. Feel free to take a look at his numbers, and that's with his coach shielding him.
QB ratings:
63.0
75.3
TD/INT:
12/20
17/13
We've gone over the lucky year he had as far as dropped picks in other threads, which would have made his numbers even worse.
Having a couple of good games in the playoffs doesn't transform his overall level, just as Eli's having a tremendous playoff run in 2007 didn't magically turn him into a top 5 QB overall.
He did show at least some improvement from year one to year two. Maybe this will be the year he elevates out of the QB basement.