Rosenberg On Record Pace

Vance Worley‘s struggles continued last night, as the Vanimal allowed 4 earned in just 4.1 IP. Worley has a 5.92 since July with opposing hitters hitting .342/.407/.490 off of the bespectacled hurler. This story could very easily be “Worley isBeing Hit Hard” but instead focuses on his 6’3″ teammate from Newport News, VA, B.J. Rosenberg. Unfortunately for Rosenberg, he is currently on the wrong side of a record setting pace.

Following the Phillies ‘pen is usually my favorite part of the season. Even in good years, the carousel of names makes things exciting, leading to a few “Who is that”s or “I saw him in Allentown”s each year. For instance, I’ll never forget Les Walrond‘s 2 IP, 4 K performance late in the 2008 season against the Nationals or the Marlins putting a three-spot on Mike Zagurski late in 2010. For 2012? I won’t forget Rosenberg’s unfortunate early June against Baltimore (an Adam Jones walk-off) and Minnesota (Trevor Plouffe with a damaging double).

Rosenberg was of particular interest of mine to follow because he wasn’t expected to be a Phillie. Rosenberg started the year in Double-A as a non-roster invitee with a number of right-handed options in front of him on the depth chart. At 26, it appeared he may stay in the minors for the foreseeable future. After a fast start to his career, injuries limited him to just 20 appearances in 2010. Rosenberg struggled in Double-A in 2010 and 2011 after showing signs of future dominance in a brief 10-game 2009 call-up but seemed to turn the corner in 2012. Equipped with a fastball, slider, and change-up, Rosenberg went 3 for 3 in save opportunities as Reading’s closer to start 2012 with a 1.12 ERA in 8 appearances and has struck-out 63 Triple-A hitters in 54 Triple-A innings as both a starter and a reliever. This should have been Rosenberg’s year.

Yet, Major League hitters thus far are finding a way to take advantage of his 85 MPH slider. In a very small sample-size, FanGraphs captures a very, very slight positive value for his fastball that sits around 94-95 MPH and shows an area of opportunity for improvement in his slider. Since these values are cumulative stats, counted similarly to WAR, a larger sample size would certainly help diagnose what has happened with Rosenberg but the slider seems to be a good place to start. For a strike-out pitcher, like Rosenberg has been in the Minors, Rosenberg has allowed hitters to be particularly patient at the plate, with hitters only chasing 27.3% of pitches outside the strike zone and 59.6% of pitches in the strike zone, all while being in the strike zone only 40.3% of the time.

These things have led Rosenberg to climbing to the of the leader board of a dubious list: Highest ERA for a Phillies reliever this century.

Nate Robertson, 2010: 54.00

Adam Bernero, 2006: 36.00

Doug Nickle, 2000: 13.50

Anderson Garcia, 2007: 13.50

B.J. Rosenberg, 2012: 12.91

Terry Adams, 2005: 12.83

Matt Smith, 2007: 11.25

J.A. Happ, 2007: 11.25

Andrew Carpenter, 2009: 11.12

Thomas Jacquez, 2000: 11.05

Scott Mathieson, 2010: 10.80

Josh Lindblom, 2012: 10.80

Rosenberg has some work to do if he wants to catch Robertson or Benero who “benefit” from their sample sizes being only 2 innings. While Rosenberg has struggled, I have been critical of the Phillies yo-yoing their bullpen arms in recent years, so I appreciate that Rosenberg may be getting an extended opportunity. And with 2012 being a lost season in terms of the playoffs, there is no better way to see if Rosenberg is a Major League pitcher than to let him pitch in the Majors. His Minor League strike-out numbers indicate that he has got a lot of potential to do the same at the Major League level but, in his short time with the Phils this year, he has shown he may need some work on locating pitches and throwing his slider more effectively. I’d be remiss to not mention Rosenberg’s string of three effective outings to start August after his recall, as well.

The tricky part becomes: what do you do with the pitchers in Triple-A who are equally deserving of a shot with the big club, namely Phillippe Aumont, Jake Diekman, and Justin De Fratus, in particular Diekman who, despite not being on the roster or starting the year on the roster, is fifth in the team in relief appearances and has 29 Ks in 21.1 IP? After battling and playing through injury, Aumont has been stellar in his last 10 appearances, notching 15 Ks in 11.2 IP for the IronPigs with a 1.54 ERA, while De Fratus has a 3.55 ERA in 12 appearances with the Pigs. With the Pigs sitting one game behind the Pawtucket Red Sox for the International League Wild Card, it is likely all three may remain on the team through the playoffs should they make them much like last season despite there being an opportunity now to replace Rosenberg or join the team in early September.