Justin Martinez

Justin Martinez

23-Year-Old PitcherRP
Arizona Diamondbacks
2025 Fantasy Outlook
Martinez struggled in his first exposure to the big leagues in 2023 and failed to break camp with the Diamondbacks last spring. The 23-year-old missed plenty of bats in the minors, striking out 14 across 6.2 innings for Triple-A Reno last year before his recall in late-April. Martinez still had trouble throwing strikes in the majors, but worked around his 11.7 percent walk rate to produce a solid 2.48 ERA over 72.2 innings. The flamethrower walked 36 to inflate his WHIP (1.31), but his splitter was absolutely devastating (.098 BAA, .122 SLG), generating a 54 percent whiff rate that was 3rd-highest in the league for that pitch type. He also averaged 100.3 mph on his sinker while inducing ground balls at a 60 percent clip. Martinez's ascension to the back-end of Arizona's bullpen was no surprise and he racked up eight of the team's 13 saves after Aug 1. He enters 2025 as the presumed favorite for saves in Arizona, but closing is no guarantee due to the traffic he allows. Read Past Outlooks
RANKS
Rest of Season From Preseason
#236
ADP
$Signed a five-year, $18 million contract extension with the Diamondbacks in March of 2025. Contract includes $7 million team option for 2030 and a $9 million team option for 2031.
Yields runs but earns save
PArizona Diamondbacks
April 27, 2025
Martinez allowed a run on one hit and two walks in one inning during Sunday's win over Atlanta. He earned a save and did not record a strikeout.
ANALYSIS
Martinez entered a 6-3 game and was not very effective. On top of the two walks, he also hit a batter. A double play before Marcell Ozuna's RBI double helped limit the damage to just one run. Martinez entered the game with a clean 0.00 ERA through nine innings. He didn't walk a batter in his first seven appearances but has now issued four free passes over his last 3.1 innings. Martinez was recently dealing with some shoulder fatigue but appears to still have a hold on the closer role.
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Pitching Stats
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2025
2024
2023
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2024 MLB Game Log
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Pitching Appearances Breakdown
Average Pitch Count
14
Last 10 Games
14
Last 5 Games
13
How many pitches does Justin Martinez generally throw?
 
1-10
 
11-20
 
21-30
 
31-40
 
41-50
 
51-60
 
61-70
 
71-80
 
81-90
 
91-100
 
101-110
 
111-120
 
121+
 
1-10
 
11-20
 
21-30
 
31-40
 
41-50
 
51-60
 
61-70
 
71-80
 
81-90
 
91-100
 
101-110
 
111-120
 
121+
 
1-10
 
11-20
 
21-30
 
31-40
 
41-50
 
51-60
 
61-70
 
71-80
 
81-90
 
91-100
 
101-110
 
111-120
 
121+
What part of the game does Justin Martinez generally pitch?
 
 
 
1st
 
 
 
2nd
 
 
 
3rd
 
 
 
4th
 
 
 
5th
 
 
 
6th
 
 
 
7th
 
 
 
8th
 
 
 
9th
 
Extra
 
 
 
1st
 
 
 
2nd
 
 
 
3rd
 
 
 
4th
 
 
 
5th
 
 
 
6th
 
 
 
7th
 
 
 
8th
 
 
 
9th
 
Extra
 
 
 
1st
 
 
 
2nd
 
 
 
3rd
 
 
 
4th
 
 
 
5th
 
 
 
6th
 
 
 
7th
 
 
 
8th
 
 
 
9th
 
Extra
% Games Reaching Innings Threshold
% Games By Number of Innings Pitched
Left/Right Pitching Splits
Since 2023
 
 
-9%
BAA vs RHP
2025
 
 
-56%
BAA vs LHP
2024
Even Split
2023
 
 
-57%
BAA vs RHP
BAA Batters K BB H 2B 3B HR
Since 2023vs Left .232 170 52 31 32 7 1 2
Since 2023vs Right .212 228 64 18 43 5 1 2
2025vs Left .063 18 8 2 1 0 0 0
2025vs Right .143 15 3 0 2 0 0 0
2024vs Left .221 127 39 22 23 5 0 1
2024vs Right .221 181 52 14 36 5 1 1
2023vs Left .444 25 5 7 8 2 1 1
2023vs Right .192 32 9 4 5 0 0 1
More Splits View More Split Stats
Home/Away Pitching Splits
Since 2023
 
 
-9%
ERA on Road
2025
No Stats
2024
 
 
-21%
ERA at Home
2023
 
 
-51%
ERA on Road
ERA WHIP IP W L SV K/9 BB/9 HR/9
Since 2023Home 3.50 1.24 43.2 4 4 3 10.3 3.7 0.2
Since 2023Away 3.19 1.46 48.0 2 3 8 12.4 5.8 0.6
2025Home 0.00 0.53 5.2 1 1 1 9.5 1.6 0.0
2025Away 0.00 0.60 3.1 0 0 1 13.5 2.7 0.0
2024Home 2.16 1.20 33.1 3 3 2 10.0 3.0 0.0
2024Away 2.75 1.40 39.1 2 3 6 12.4 5.7 0.5
2023Home 17.36 2.36 4.2 0 0 0 13.5 11.6 1.9
2023Away 8.44 2.44 5.1 0 0 1 11.8 8.4 1.7
More Splits View More Split Stats
Stat Review
How does Justin Martinez compare to other relievers?
This section compares his stats with all relief pitcher seasons from the previous three seasons (minimum 30 innings)*. The bar represents the player's percentile rank. For example, if the bar is halfway across, then the player falls into the 50th percentile for that stat and it would be considered average.

* Exit Velocity, Barrels/BBE %, Balls Hit 95+ MPH %, and Spin Rate are benchmarked against 2019 data (min 30 IP). See here for more exit velocity/barrels stats plus an explanation of current limitations with that data set.
  • K/BB
    Strikeout to walk ratio.
  • K/9
    Average strikeouts per nine innings.
  • BB/9
    Average walks per nine innings.
  • HR/9
    Average home runs allowed per nine innings.
  • Fastball
    Average fastball velocity.
  • ERA
    Earned run average. The average earned runs allowed per nine innings.
  • WHIP
    Walks plus hits per inning pitched.
  • BABIP
    Batting average on balls in play. Measures how many balls in play against a pitcher go for hits.
  • GB/FB
    Groundball to flyball ratio. The higher the number, the more likely a pitcher is to induce groundballs.
  • Left On Base
    The percentage of base runners that a pitcher strands on base over the course of a season.
  • Exit Velocity
    The speed of the baseball as it comes off the bat, immediately after a batter makes contact.
  • Barrels/BBE
    The percentage of batted ball events resulting in a Barrel. A Barrel is a batted ball with similar exit velocity and launch angle to past ones that led to a minimum .500 batting average and 1.500 slugging percentage.
  • Spin Rate
    Spin Rate is the rate of spin on a baseball after it is released. It is measured in revolutions per minute (rpm).
  • Balls Hit 95+ MPH
    The percentage of batted balls hit that met or exceeded the 95 MPH threshold.
  • Swinging Strike
    The percentage of pitches that result in a swing and a miss.
K/BB
5.50
 
K/9
11.0
 
BB/9
2.0
 
HR/9
0.0
 
Fastball
100.4 mph
 
ERA
0.00
 
WHIP
0.56
 
BABIP
.173
 
GB/FB
2.40
 
Left On Base
80.0%
 
Exit Velocity
73.6 mph
 
Barrels/BBE
0.0%
 
Spin Rate
1880 rpm
 
Balls Hit 95+ MPH
6.9%
 
Swinging Strike
14.5%
 
Prospect Rankings History
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Defensive Stats
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Stats Vs Today's Lineup
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More Fantasy News
Fires clean ninth inning in return
PArizona Diamondbacks
April 23, 2025
Martinez (shoulder) returned to the mound in Wednesday's extra-inning loss to the Rays, striking out one during a clean ninth inning.
ANALYSIS
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Battling shoulder fatigue
PArizona Diamondbacks
Shoulder
April 23, 2025
Diamondbacks manager Torey Lovullo said Tuesday that Martinez is dealing with right shoulder fatigue, Jack Sommers of SI.com reports.
ANALYSIS
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Was unavailable due to fatigue
PArizona Diamondbacks
April 22, 2025
Diamondbacks manager Torey Lovullo said that Martinez was unavailable to pitch in Sunday's extra-innings win over the Cubs due to "fatigue" and a recent heavy workload, Jack Sommers of SI.com reports.
ANALYSIS
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Stepping in as full-time closer
PArizona Diamondbacks
April 20, 2025
Martinez is expected to be the Diamondbacks' primary closer after the team placed A.J. Puk (elbow) on the 15-day injured list Saturday.
ANALYSIS
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Finishes off Miami
PArizona Diamondbacks
April 17, 2025
Martinez worked a scoreless inning, retiring all three batters he faced in Wednesday's 6-2 win over the Marlins.
ANALYSIS
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