I mean, if he's 2010 Sanchez (extremely unlikely), it would be pretty amazing. But he won't be. And we don't need any more "maybe" pitchers. Our entire rotation consists of "maybe" pitchers.
IMO, Liriano, Locke, and McPherson ALL have a significantly higher probability of success as starters than does Sanchez. But Sanchez used to be good and he's only 30 and a lefty..... so I agree that he's OK as bullpen or starter depth.