Did Sterling Knight get fired from Sonny?

Can you imagine Sonny With a Chance without Sterling Knight? Well, turns out he originally filmed the pilot for Sonny as a different character than Chad Dylan Cooper. The show got picked up, but his character didn't. "I wasn't exactly fired, but I wasn't exactly hired either," he says. "They were real sweet about it. they told me it wasn't anything I did." But then the writers created the role of Chad just for him. Duh- who wouldn't want face around?!