Merrill Kelly

Active

Arizona Diamondbacks · Pitcher

Age 376' 2" · 202 lbsThrows Right

FBaseball Overview

At 37 years old, Kelly offers Arizona a veteran innings-eater, though his 2026 season has been disappointing compared to his solid 2025 campaign when he posted a 3.52 ERA with 167 strikeouts across 184 innings. His early-season struggles are evident in an inflated 5.84 ERA and 1.53 WHIP across 81.2 innings, signaling potential decline at an advanced age despite maintaining modest strikeout production at 47 K. Fantasy managers should view him as a streaming option rather than a reliable anchor, as his ERA and WHIP trends suggest durability issues and diminished effectiveness that make him risky for consistency in most formats. His win-loss record (5-8) and lack of save opportunities further limit his upside, making him best suited for deeper leagues where streaming pitchers is a necessity.

MLB Pitching

Year	Team	G	GS	W	L	ERA	WHIP	K	IP	BB
2019	Arizona Diamondbacks	32	32	13	14	4.42	1.31	158	183.1	57
2020	Arizona Diamondbacks	5	5	3	2	2.59	0.99	29	31.1	5
2021	Arizona Diamondbacks	27	27	7	11	4.44	1.29	130	158.0	41
2022	Arizona Diamondbacks	33	33	13	8	3.37	1.14	177	200.1	61
2023	Arizona Diamondbacks	30	30	12	8	3.29	1.19	187	177.2	69
2024	Arizona Diamondbacks	13	13	5	1	4.03	1.17	63	73.2	19
2025	2 teams▼	32	32	12	9	3.52	1.11	167	184.0	48
2026	Arizona Diamondbacks	15	15	6	8	5.71	1.56	53	86.2	35
Career	Totals	187	187	71	61	3.92	1.23	964	1095	335

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

Minor League Pitching

Year	Team	G	GS	W	L	ERA	WHIP	K	IP	BB
2010	2 teams▼	12	3	1	2	4.30	1.17	29	37.2	13
2011	Charlotte Stone Crabs	25	23	8	7	3.28	1.30	70	129.0	51
2012	Montgomery Biscuits	32	9	8	3	3.57	1.27	61	88.1	28
2013	2 teams▼	28	26	13	10	3.64	1.22	111	158.1	65
2014	Durham Bulls	28	15	9	4	2.76	1.26	108	114.0	37
2021	ACL D-backs	1	1	0	0	4.50	1.25	7	4.0	2
2024	Hillsboro Hops	1	1	0	0	6.75	1.50	2	4.0	0
2026	Reno Aces	1	1	1	0	0.00	0.80	2	5.0	2
Career	Totals	128	79	40	26	3.40	1.25	390	540.1	198

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 Velo92.2 mph

Avg Spin2315 rpm

Whiff %20.9%

K %13.7%

BB %9.0%

Hard Hit %43.8%

Barrel %14.5%

xERA7.78

xBA Against0.311

xSLG Against0.594

BA Against0.291

SLG Against0.532

GB%39.2%

FB%27.7%

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

2019

Arizona Diamondbacks

4.42

1.31

158

183.1

2020

Arizona Diamondbacks

2.59

0.99

31.1

2021

Arizona Diamondbacks

4.44

1.29

130

158.0

2022

Arizona Diamondbacks

3.37

1.14

177

200.1

2023

Arizona Diamondbacks

3.29

1.19

187

177.2

2024

Arizona Diamondbacks

4.03

1.17

73.2

2025

2 teams▼

3.52

1.11

167

184.0

2026

Arizona Diamondbacks

5.71

1.56

86.2

Career

Totals

187

3.92

1.23

964

1095

335

Year

Team

ERA

WHIP

2010

2 teams▼

4.30

1.17

37.2

2011

Charlotte Stone Crabs

3.28

1.30

129.0

2012

Montgomery Biscuits

3.57

1.27

88.1

2013

2 teams▼

3.64

1.22

111

158.1

2014

Durham Bulls

2.76

1.26

108

114.0

2021

ACL D-backs

4.50

1.25

4.0

2024

Hillsboro Hops

6.75

1.50

4.0

2026

Reno Aces

0.00

0.80

5.0

Career

Totals

128

3.40

1.25

390

540.1

198