What should we expect from Genesis Cabrera in his MLB debut?

Michael Wacha was one of the worst starters in Major League Baseball before the St. Louis Cardinals mercifully removed him from the rotation. What was Wacha so bad? The veteran hero of the 2013 NLCS couldn’t throw strikes.

Michael Wacha as Starter:  2019

IP	TBF	K	K%	BB	BB%	HR/FB	ERA	FIP	xFIP
46.2	215	43	20.0	29	13.5	19.6	5.99	5.65	5.02

That’s ugly. The only thing odd about the Cardinals’ decision to remove Wacha from the rotation is why it took so long. A club that intends to compete can’t afford to have a pitcher in the rotation who can’t throw strikes. Naturally, Cardinals management has decided to replace Wacha with lefty prospect Genesis Cabrera, who can’t throw strikes.

Consider his performance at each level of the minors, as reflected in the stats in the following table (excluding the two innings he notched with Triple-A Memphis in 2018).

Genesis Cabrera in Minors: 2014–2019

Year	Level	IP	TBF	K%	BB%	HR/FB	ERA	FIP	xFIP
2014	R	29.1	110	23.6	2.7	0.0	2.45	1.94	2.26
2015	R	17	69	27.5	5.8	0.0	3.18	2.34	3.18
2016	A	116	489	19.6	9.8	6.6	3.88	4.20	4.04
2017	High-A	69.2	274	21.9	9.1	3.7	2.84	3.35	3.77
2017	AA	64.2	295	17.3	9.2	6.6	3.62	4.13	4.31
2018	AA (TB)	113.2	474	26.2	12.0	8.7	4.12	4.00	4.00
2018	AA (STL)	24.2	107	19.6	12.2	8.6	4.74	4.91	5.14
2019	AAA	39.2	182	21.4	10.4	18.3	6.35	6.85	6.35

Cabrera’s stats the last two seasons (especially those in the St. Louis system) are not those of a prospect who has figured out the high minors. The Cardinals are replacing a failed MLB starter in Wacha who has walked too many batters and given up too many home runs in the majors with a prospect who has walked too many batters and given up too many home runs in the minors.

To be sure, Cabrera has enticing stuff and a track record in the low minors that is heartening, but there is little objective evidence upon which to base a belief that the young southpaw will succeed as a starter in the majors in 2019. For a team in the middle of a terrible slump that has one of the worst rotations in the National League, Cabrera’s promotion is curious to say the least. This feels more like a “see what we have” move than a “win now” move for the Cardinals, even if it is for just a start or two until Alex Reyes is ready to stake his claim to a spot in the St. Louis rotation.

All of this is to say that, in Cabrera’s debut, there is little reason for us to expect the rookie’s performance to be any better than Wacha’s was before the Cardinals justifiably removed the veteran from the rotation. If Cabrera struggles, as seems likely, he will likely struggle in the same way that Wacha was struggling. That’s because Cabrera has been bad in Triple-A in the same way that Wacha was bad in the majors.