Dereck Rodriguez made quite an impression in his MLB debut, seemingly coming out of nowhere to entrench himself in the Giants’ rotation. The son of Ivan Rodriguez, it would be hard to argue against the excitement of these numbers from 2018:
89 Strikeouts (6.77 K/9)
36 Walks (2.74 BB/9)
39.5% Groundball Rate
Obviously he benefited from some luck, given the BABIP and his 39.4% Hard%. That alone would bring questions as to his ability to reasonably replicate last year’s success. The problem is things only get worse…
The owner of a minor league career 7.8 K/9, Rodriguez didn’t show much swing and miss potential in his first taste of the Majors (Whiff%):
- Changeup – 13.03%
- Fourseam Fastball – 10.72%
- Curveball – 9.71%
- Slider – 9.39%
- Sinker – 5.63%
He has a diverse repertoire, throwing all five of his pitches at least 11.44% of the time. However none of them appear to bring swing and miss potential. His strikeout rate got worse with each passing month, as opposing teams got a better look at him, finishing with a 5.60 K/9 in 27.1 IP in September.
That doesn’t speak to a high upside, and that alone will drag down his appeal.
They weren’t an issue in 2018, with a 0.68 HR/9 in the Majors. Prior to his promotion he had a 1.97 HR/9 over 50.1 IP at Triple-A, after a 1.08 over 75.1 IP at Double-A in ’17. The owner of a 39.5% groundball rate in the Majors, while he could benefit from pitching half his games in San Francisco it’s a near lock that he sees a significant regression.
While Rodriguez does have solid control (minor league career 2.4 BB/9), everything else points to a significant drop-off:
- Limited strikeout rate
- Significant home run concerns
- Regression in luck
That is a formula for disaster, and it’s very plausible that he pitches his way out of the Giants’ rotation. Even if he sticks, an ERA north of 4.00 is likely (and a 4.50+ isn’t unreasonable). Let someone else get excited and pay the price.
Sources – Fangraphs, Brooks Baseball, Baseball Reference