But his performance looks decent enough to me.

http://www.stltoday.com/blogzone/bird-land/bird-land/2009/06/cardinals-release-former-first-rounder-tyler-herron/

"He was not progressing the way we needed or expected him to," Luhnow wrote in a text message. "We need to give the valuable innings to other players who deserve the opportunity."

Smells fishy.

Yeah, his numbers aren’t spectacular. They’re pretty mediocre. But he’s only 22 and I wouldn’t say he’s flamed out.

I’m gonna say pretty definitively that unless the Cardinals have 10 or 15 top pitching prospects (and they don’t as far as I know), this is absolutely not a performance issue. At least, performance isn’t more than 10 or 15% of the reason.