With Soria's injury, I have read on some other websites (non-Royals based) that Aaron Crow should be an option for the closer. I just never really considered him as an option. His production dropped significantly in the 2nd half of the season after being the Royals lone All-Star participant. Here is a look at his 2nd half down turn and why he should not be in consideration as the closer because he has problems with left-handed hitters.
Aaron had a good first half of the season, but collapsed in the second half as seen by these numbers:
First 3 months: 1.40 ERA, 0.239 BABIP, 9.1 K/9, 4.0 BB/9, 2 Blown Saves, 8 Holds,
Last 3 months: 5.01 ERA, 0.373 BABIP, 10.0 K/9, 5.4 BB/9, 5 Blown Saves, 0 Holds
With generally similar walk and strikeout rates in the second half of the season, a high BABIP materialized and his production dropped.
One cause for the drop could have been a slower and therefore an easier to hit fastball has seen here:
This spring he is being stretched out to be a starter (who generally have lower velocities) and his velocity looks similar to the end of last season (just one appearance has Pitch FX data). He has lost a couple of MPH from his great first half of 2011:
Because of his inability to get batters out in the 2nd half of the season, I believe the team does trust him yet for the closer role.
Another problem with Crow is that he has problems getting out left-handed hitters.
Here are the RH vs LH splits for Crow, Broxton, and Holland:
vs RHH 10.2 K/9, 4.8 BB/9, 0.229 BABIP, 3.41 FIP
VS LHH 8.31 K/9, 4.2 BB/9, 0.354 BABIP, 5.06 FIP
vs RHH 10.1 K/9, 2.2 BB/9, 0.264 BABIP, 3.06 FIP
VS LHH 12.4 K/9, 4.2 BB/9, 0.313 BABIP, 2.07 FIP
vs RHH 11.5 K/9, 2.3 BB/9, 0.314 BABIP, 2.30 FIP
VS LHH 11.6 K/9, 5.6 BB/9, 0.313 BABIP, 3.22 FIP
Crow struggled to get left-handed hitters out compared to the other two closer canidates. A closer is going to have to be able to get out players from both sides of the plate. This issue is going to become more evident if he is a starter. Developing an off speed pitch will help with getting LHH out, but he is not using one yet on a regular basis.
If Crow doesn't make it as a starter, he should not even be considered to be the closer. His production from the first half of 2011 was not sustainable and he has problems getting out LHH. Right now Crow's role looks to be as a ROOGY setup man in the bullpen.