Wacha vs. Lyons: Who stays in the rotation?

Jake Westbrook will be returning to the rotation tonight for the Cardinals.  Owner of a 1.62 ERA through six starts and 39 IP before going on the DL, it was assumed he would return to the rotation when ready.  What wasn’t assumed however, was who he would replace. 

Gast and Lyons both replaced Westbrook and Garcia when they went down, with Wacha replacing Gast when he subsequently had his own DL stint.  Westbrook will be taking Lyon’s spot in the rotation, but Matheny and the Cardinals have yet to decide if it will be Lyons or Wacha that ultimately loses the spot, or where the person being replaced will head to the bullpen or back to Triple-A Memphis.  Let’s look at the stats for who should stay and who should go. All stats are provided by www.fangraphs.com.

	GS	W	L	IP	K/9	BB/9	HR/9	BABIP	LOB%	ERA	FIP	WAR
Wacha	3	1	0	17.2	7.13	2.04	1.02	.283	65.9%	4.58	3.63	0.2
Lyons	4	2	2	25.2	4.91	1.75	1.05	.224	72.1%	3.51	4.08	0.1

-For those that are unfamiliar with sabermetrics, here is an explanation on BABIP, LOB%, FIP, and WAR.  

The first thing that stands out to me is Wacha's much higher strikeouts per nine innings than Lyons, 7.13 to 4.91.  This can be explained by Wacha's ability to blow a mid-90's fastball by hitters compared to Lyons' pitch-to-contact strategy.  BABIP looks to be a problem for Lyons.  A .224 BABIP is simply not sustainable, especially since he's a ground ball pitcher.  He will get hit more often in future starts if he stays in the majors. Lyons also has been more successful at leaving runners on base.  He is hovering around the league average but Wacha has been unlucky in only leaving on 65.9% of runners despite striking out more batters.  

You would expect Lyons to have performed better considering a superior ERA to Wacha. However, Wacha's much higher K/9 and Lyons' unsustainable BABIP gives Wacha the stronger FIP.  ERA takes a long time to be a good indication of a pitcher's talent level compared to K/9 and BB/9.  While Lyons has given a few less walks he's way behind in strikeouts.  And once you consider he's getting lucky on balls hit in play and Wacha has been unlucky in leaving runners on base, it begins to paint a picture.

Now, with four and three starts each at the big league level, the stats are not much to go on.  However, they convincingly give Wacha the edge.  Lyons has been a strong fill-in and I've been happy with his performance, but he appears to be the odd man out here.  But where will he go?  Will he head to the bullpen or back to Memphis?  Perhaps Matheny would prefer another reliable arm in the bullpen.  Besides the trio of Maness, Rosenthal, and Mujica, and the left-handed specialist Choate, the Cardinals haven't had much luck with relievers.  Or the Cardinals could decide to continue to condition Lyons as a starter and have him keep making starts at Triple-A.  After all, Matheny is currently trying out Siegrist and Butler in middle relief roles with limited success and Lyons would likely be the first option if anymore starting pitcher injuries occur.  Lyons could also be a trade chip to another team down the stretch if we make a trade before the deadline.  I would bet that Lyons will end up going back to Memphis, though he should hold his head high for a strong first stint in the majors.

But one thing seems apparent:  Although Wacha has a higher ERA, he has performed better than Lyons so far at the big league level.  And with Wacha-mania in full effect, it seems likely that he is staying in the rotation, at least for now.  Thanks for reading.  If you enjoyed it than please continue to check back to this page in the future for more commentary on one of the greatest franchises in sports, the St. Louis Cardinals.