Phillies prospect Rosenberg learning outside the bullpen

Last spring training, B.J. Rosenberg was an under-theradar bullpen prospect who had an opportunity to establish himself as a legitimate part of the Phillies' future plans.

Now, he's trying to make up for lost time.

The Phillies have moved the righthander from the bullpen to the rotation at Double A Reading, hoping to give him more regular work at honing his game. They still project him as a reliever. But, much like Phillippe Aumont last season, they feel as though he will have more of an opportunity to develop with the regular work of a starter.

While young relievers like Antonio Bastardo, Michael Stutes and Justin De Fratus have emerged as some of the more promising relief arms in the organization, Rosenberg still has the potential to pitch his way into such standing. As a 23-year-old at Class A Lakewood in 2009, he went 7-2 with a 0.89 ERA, 19 saves, 65 strikeouts and 10 walks in 50 innings. The Phillies jumped him straight from low-A to Double A, but early last season he suffered a lat strain that sidelined him for much of the year. He ended up appearing in just 20 games, posting a 5.20 ERA, 10.7 K/9 and 2.9 BB/9 in 27 innings.

This year, Rosenberg has a 1.88 ERA, 10.7 K/9 and 1.6 BB/9 in two starts and 11 relief appearances. If he continues at his current progression, he could find himself back in big-league camp next season.

- David Murphy