He couldn't of course, but he was on the bench because his coaching staff believed that his meager 73 passer rating was as good as he could ever get.
In the meantime, they were convinced that Sanchez's meager 78 passer rating would improve because of his "developing talent."
They saw Tebow as a utility player and Sanchez as a franchise player.
They were clearly wrong about Sanchez - they were probably wrong about Tebow too.
Benchmarks!...there were no benchmarks...