That's not "only", that's the whole point. That's a flawed point. Zambrano relieved in the minors, That's a ridiculous comparison. Zambrano started 24 games at age 18 in A ball and was pretty decent, playing pro ball. He went into the pen for a bit the next year, but it was always noted that he could maintain high 90's into the late innings. And at age 20 he started 24 more games in AAA. Cashner was a nothing prospect as a starter and only got hype once he went to the pen. Cashner and Zambrano are horrible comparisons for career path. Cashner has shown absolutely no ability to be an actual starter, unless you just want to get 4-5 innings out of him every time. Cashner is 22 years old and averaged 4.2 innings in 24 starts this year. Zambrano made 32 starts in the major leagues at 22, pitching 214 innings. Your talking about a time period where the Cubs weren't implementing strict pitch counts. We have no idea how long deep Cashner is capable of going in games, because the Cubs have determined it isn't important at this point. Looking at his stats this year, it is easy to see to see that Cashner has the potential to be an above average starter. His numbers, when the Cubs let him pitch, are pretty good. About the only thing he doesn't have going for him are ridiculous strikeout numbers in AA. His WHIP was a very respectable 1.11 in High A and 1.23 in AA, and that was driven mainly by a high level of walks. So the batters clearly weren't squaring up the ball very well. Either way, that is a pretty good position to be at, when your perceived floor is being a dominant reliever.