Luis Castillo

Active

Seattle Mariners · Pitcher

Age 336' 2" · 200 lbsThrows Right

FBaseball Overview

At 33 years old, Castillo enters 2026 as a veteran rotation anchor for Seattle, though his early-season performance signals a decline from his stellar 2025 campaign. His 4.93 ERA and 1.36 WHIP through mid-season represent a significant step backward from last year's 3.54 ERA and 1.18 WHIP, suggesting he may be losing velocity or command at an advanced age. The strikeout production remains respectable with 73 K through 76.2 innings, but the win-loss record and inflated ERA make him a risky fantasy commodity this season. Fantasy managers should approach Castillo with caution, viewing him as a back-of-rotation streamer rather than a dependable weekly starter, particularly in ERA and WHIP-sensitive formats.

MLB Pitching

Year	Team	G	GS	W	L	ERA	WHIP	K	IP	BB
2017	Cincinnati Reds	15	15	3	7	3.12	1.07	98	89.1	32
2018	Cincinnati Reds	31	31	10	12	4.30	1.22	165	169.2	49
2019	Cincinnati Reds	32	32	15	8	3.40	1.14	226	190.2	79
2020	Cincinnati Reds	12	12	4	6	3.21	1.23	89	70.0	24
2021	Cincinnati Reds	33	33	8	16	3.98	1.36	192	187.2	75
2022	2 teams▼	25	25	8	6	2.99	1.08	167	150.1	45
2023	Seattle Mariners	33	33	14	9	3.34	1.10	219	197.0	56
2024	Seattle Mariners	30	30	11	12	3.64	1.17	175	175.1	47
2025	Seattle Mariners	32	32	11	8	3.54	1.18	162	180.2	46
2026	Seattle Mariners	17	14	3	7	4.79	1.33	77	82.2	27
Career	Totals	260	257	87	91	3.62	1.19	1570	1493.1	480

Source: MLB Stats API · Multi-team seasons show combined totals — click to expand

Minor League Pitching

Year	Team	G	GS	W	L	SV	ERA	WHIP	K	IP	BB
2012	DSL Giants	19	0	1	3	2	3.31	1.27	47	54.1	22
2013	DSL Giants	27	0	0	1	20	0.64	0.64	34	28.1	3
2014	Augusta GreenJackets	48	0	2	2	10	3.07	1.38	66	58.2	25
2015	2 teams▼	35	16	6	6	4	3.20	1.27	94	107	33
2016	2 teams▼	26	24	8	6	0	2.26	1.00	103	131.2	25
2017	Pensacola Blue Wahoos	14	14	4	4	0	2.58	1.01	81	80.1	13
2022	2 teams▼	3	3	0	0	0	0.87	1.45	16	10.1	8
Career	Totals	172	57	21	22	36	2.62	1.13	441	470.2	129

Source: MLB Stats API · Multi-team seasons show combined totals — click to expand

Game Log2026 season

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Pitching Analytics2026 season · via Baseball Savant

Click for year to year changes

FB Velo95.3 mph

Avg Spin2194 rpm

Whiff %24.0%

K %21.1%

BB %7.4%

Hard Hit %44.1%

Barrel %9.0%

xERA4.55

xBA Against0.261

xSLG Against0.429

BA Against0.255

SLG Against0.406

GB%38.4%

FB%26.7%

What These Stats Mean

FB Velo — Average fastball velocity. Harder throwers generate more swings and misses, setting up every other pitch in their arsenal. Velocity is the foundation of strikeout upside.

Avg Spin — Average spin rate across all pitches. Higher spin creates more movement and makes pitches harder to square up — elite spinners run better strikeout and batting average against numbers.

Whiff % — Swings-and-misses per swing. The most direct measure of a pitcher's ability to miss bats and the best leading indicator of strikeout rate.

K % — Strikeout rate per batter faced. The core fantasy pitching stat — high K% means reliable strikeout totals that hold up even in shorter starts.

BB % — Walk rate per batter faced. The primary control metric. High BB% tanks ERA and WHIP and keeps baserunners on constantly. Elite starters typically run below 7%.

Hard Hit % — Percentage of batted balls hit 95 mph or harder against. Low hard-hit% means weak contact, protecting both ERA and the defense behind the pitcher.

Barrel % — Percentage of batted balls barreled against. The most direct home run predictor — low barrel% pitchers rarely give up long balls.

xERA — Expected ERA based on contact quality allowed, removing the effect of sequencing, luck, and defense. Better predictor of future ERA than ERA itself.

xBA Against — Expected batting average opponents should hit based on contact quality. A gap between xBA and actual BA indicates unsustainable luck in either direction.

xSLG Against — Expected slugging allowed based on contact quality. High xSLG against predicts future extra-base damage; low xSLG means the pitcher is genuinely suppressing power.

BA Against — Actual batting average opponents are hitting — a key WHIP component. Check xBA to see if the number is sustainable.

SLG Against — Actual slugging allowed. Captures hits, doubles, triples, and home runs — lower means the pitcher is limiting the power damage he gives up.

GB% — Ground ball rate. High GB% pitchers generate double plays, limit home runs, and keep the ball in the park — great for protecting ERA and WHIP ratios.

FB% — Fly ball rate. High FB% pitchers give up more air contact — dangerous when combined with high exit velocity, less so when contact is soft.

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Year

Team

ERA

WHIP

2017

Cincinnati Reds

3.12

1.07

89.1

2018

Cincinnati Reds

4.30

1.22

165

169.2

2019

Cincinnati Reds

3.40

1.14

226

190.2

2020

Cincinnati Reds

3.21

1.23

70.0

2021

Cincinnati Reds

3.98

1.36

192

187.2

2022

2 teams▼

2.99

1.08

167

150.1

2023

Seattle Mariners

3.34

1.10

219

197.0

2024

Seattle Mariners

3.64

1.17

175

175.1

2025

Seattle Mariners

3.54

1.18

162

180.2

2026

Seattle Mariners

4.79

1.33

82.2

Career

Totals

260

257

3.62

1.19

1570

1493.1

480

Year

Team

ERA

WHIP

2012

DSL Giants

3.31

1.27

54.1

2013

DSL Giants

0.64

28.1

2014

Augusta GreenJackets

3.07

1.38

58.2

2015

2 teams▼

3.20

1.27

107

2016

2 teams▼

2.26

1.00

103

131.2

2017

Pensacola Blue Wahoos

2.58

1.01

80.1

2022

2 teams▼

0.87

1.45

10.1

Career

Totals

172

2.62

1.13

441

470.2

129