Justin Martinez

Active

Arizona Diamondbacks · Pitcher

Age 256' 3" · 225 lbsThrows Right

#300 Dynasty

News Updates

Justin Martinez makes season debut for D-backs
Arizona Diamondbacks pitcher Justin Martinez made his 2026 season debut, allowing one walk over a scoreless inning in the team's 9-4 loss to Boston. This call-up provides depth to the bullpen as the team navigates the second half.
Aug 19, 2026
Martinez advances rehab assignment with strong outing
Justin Martinez, working his way back from elbow issues, pitched a scoreless inning for Triple-A Reno on Tuesday without allowing a hit or walk while striking out two batters. His successful rehab performance suggests he may be nearing a return to the Arizona Diamondbacks' active roster.
Aug 13, 2026

MLB Pitching

Year	Team	G	W	L	SV	ERA	WHIP	K	IP	BB
2023	Arizona Diamondbacks	10	0	0	1	12.60	2.40	14	10.0	11
2024	Arizona Diamondbacks	64	5	6	8	2.48	1.31	91	72.2	36
2025	Arizona Diamondbacks	17	1	2	5	4.11	1.24	22	15.1	12
2026	Arizona Diamondbacks	7	2	0	0	0.00	1.05	8	6.2	5
Career	Totals	98	8	8	14	3.53	1.39	135	104.2	64

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
2018	2 teams▼	15	12	0	5	0	7.57	2.02	30	44.0	38
2019	2 teams▼	15	10	1	3	1	3.12	1.42	71	52.0	33
2021	Visalia Rawhide	7	7	1	3	0	6.65	1.74	24	23.0	15
2022	5 teams▼	2	0	0	1	0	9.00	1.50	2	2.0	1
2023	Reno Aces	47	0	2	1	9	4.20	1.64	67	49.1	48
2024	Reno Aces	6	0	0	0	3	2.70	1.05	14	6.2	3
2025	2 teams▼	2	1	0	0	0	0.00	0.50	1	2	0
2026	2 teams▼	4	2	0	0	0	0.00	0.25	6	4	1
Career	Totals	116	32	7	15	14	4.56	1.58	275	219	160

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

Game Log2026 MLB

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Advanced Stats2026 season · via Baseball Savant

Click for year to year changes

FB Velo101.5 mph

Avg Spin1854 rpm

Whiff %24.0%

K %28.6%

BB %17.9%

Hard Hit %21.4%

Barrel %0.0%

xERA2.72

xBA Against0.138

xSLG Against0.175

BA Against0.091

SLG Against0.091

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.

Articles featuring Justin Martinez

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Year

Team

ERA

WHIP

2023

Arizona Diamondbacks

12.60

2.40

10.0

2024

Arizona Diamondbacks

2.48

1.31

72.2

2025

Arizona Diamondbacks

4.11

1.24

15.1

2026

Arizona Diamondbacks

0.00

1.05

6.2

Career

Totals

3.53

1.39

135

104.2

Year

Team

ERA

WHIP

2018

2 teams▼

7.57

2.02

44.0

2019

2 teams▼

3.12

1.42

52.0

2021

Visalia Rawhide

6.65

1.74

23.0

2022

5 teams▼

9.00

1.50

2.0

2023

Reno Aces

4.20

1.64

49.1

2024

Reno Aces

2.70

1.05

6.2

2025

2 teams▼

0.00

0.50

2026

2 teams▼

0.00

0.25

Career

Totals

116

4.56

1.58

275

219

160