With little fanfare, B.J. Rosenberg quietly became a Phillie on June 9, replacing Raul Valdes early on a Saturday morning. Charlie Manuel wasted no time using Rosenberg and put him in a tie game in the 11th. Rosenberg retired the first three Orioles he faced, earning him the 12th. Adam Jones hit a 2-run shot in the 12th off Rosenberg, however, and Rosenberg’s first day in the Major Leagues ended with a walk-off loss in the seaport.
Unfortunately, this was the story for a lot of Rosenberg’s year. Rosenberg had such promising Minor League years (1.00 ERA in Williamsport in 2008, 0.89 ERA in Clearwater and 2.53 ERA in Reading in 2009) before injuries slowed him down in 2010. To see Rosenberg overcome those injuries and reach the Majors in 2012 was a treat and admittedly, I was rooting pretty hard for him to succeed.
Rosenberg jumped two levels in 2012 and earned his call to the Majors by being dominant in both (1.13 ERA, 11.25 K/9 IP at Reading, 2.00 ERA, 10.50 K/9 IP at Lehigh Valley). His 96-97 MPH fastball was able to get by a lot of Minor League hitters but became one of his biggest obstacles in the Majors. Rosenberg struggled to place his fastball in June and after three appearances, was sent back down to Lehigh Valley, where he appeared as both a starter and reliever.
Rosenberg’s final numbers with the Phils in 2012 were pretty bad (6.12 ERA, 5.04 BB/9 IP), but there is reason to believe he made adjustments throughout the season that will benefit him in 2013. Rosenberg was called up again in August where he ran into rough outings against the Marlins, Brewers, and Mets. But in September, Rosenberg had a 1.26 ERA in 14.1 IP with 12 Ks and 6 BBs, a pretty good line. It’s tough to determine where the adjustment was made but if I had to pinpoint it, September 9 against the Rockies is a good place to start. Rosenberg looked infinitely more confident with his fast ball and relied less on his slider. He mowed down two of the three Rockies he faced, earned his first MLB win, and his possible case of rosacea became endearing to hundreds of thousands of Phillies fans when Manuel discussed it in the post-game.
Final Thoughts: Rosenberg had a string of incredibly rough appearances to start his MLB career but the Phillies saw something in him to stick with him. The bullpen will be crowded to start 2013 but I would not count Rosenberg out of the mix. His fastball maxed out at 97.9 MPH this year according to FanGraphs and he was undoubtedly placing it more effectively in his final month with the club. It is really hard to give anything above a D+ for a 6.12 ERA but it was in limited playing time and his September was among the best of the Phillies relievers. Grade: C-.