Zack Von Rosenberg made the switch to a two-seam fastball this year.

When Zack Von Rosenberg was drafted, the Pittsburgh Pirates didn't have any ace pitching prospects. Jameson Taillon was a year away from being drafted. Luis Heredia was a year and a few months away from being signed. Gerrit Cole was two years away from being drafted. And the last time the Pirates had an ace in the majors was arguably when Doug Drabek was on the team.

The hope with the 2009 draft class was that one of those pitchers could emerge as a top of the rotation guy. Guys like Taillon and Cole had top of the rotation upside when they were drafted. With Von Rosenberg and company, the hope was that one of them could add velocity, or just have the overall combination of stuff and the ability to pitch which would...

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