2025 Fantasy Baseball: Arizona Diamondbacks Closer Depth Chart
When watching the below video of Justin Martinez, the fantasy market will get giddy about his closing potential in 2025. His rise to stardom starts with better command.
"Video Game Stuff" 🕹️
— Rob Friedman (@PitchingNinja) July 5, 2024
from Justin Martínez pic.twitter.com/SMfyS1wN3N
RP – Justin Martinez, ARI (197.80)
The Diamondbacks signed Martinez at age 16 after converting from outfield to a pitcher, but his arm didn’t fire over six seasons in the minors (7-15 with a 4.60 ERA, 1.613 WHIP, 163 strikeouts over 217.0 innings with 14 saves). His high inning count was 56.0 in 2019 at rookie ball. He has TJ surgery in 2021. Martinez walked 6.8 batters per nine in Arizona’s farm system.
Batters got the best of him over 10 appearances with the Diamondbacks in 2023 (14 runs, 24 baserunners, and two home runs over 10.0 with 14 strikeouts and one save). After 6.2 innings of work at AAA (2.70 ERA and 14 strikeouts) last season, Arizona called him up in mid-April. Martinez walked 14 batters over his first 25.0 innings, but he was challenging to hit (.174 BAA) while delivering 28 strikeouts.
From mid-June to July 28th, his outcomes (4.43 ERA and 1.328 WHIP) hurt fantasy teams. The Diamondbacks gave him save chances in August (seven converted), but his arm didn’t belong in high-pressure situations over his final 16 appearances (nine runs, 27 baserunners, and 24 strikeouts over 17.1 innings).
Martinez had equal success against right-handed (.221 BAA) and left-handed batters (.221 BAA). His average sinker (100.2) was in the upper tier of major league baseball. Batters rarely made hard contact with his split-finger fastball (.089 BAA), slider (.178 BAA), and low-volume four-seamer (.192 BAA). Between his failed slider (.325 BAA) and high heater, he had 21 walks and 24 strikeouts, showcasing his need for better command. His walk rate (4.5) improved from his minor league levels.
Fantasy Outlook: When adding a high groundball rate (58.9) to his ability to strike batters out, Martinez isn’t far off from being a dominating, trusted late-inning arm. Unfortunately, his free passes will get him in trouble and create many bad innings. Arizona will give him chances at saves, and he may survive for a month or two when he is in rhythm. I expect WHIP risk early in his career. Martinez's upside does outweigh his failure risk.
AJ Puk, K'ing the Side...with 2 Swords. ⚔️⚔️ pic.twitter.com/NmJkhUhzPu
— Rob Friedman (@PitchingNinja) August 25, 2024
Top Diamondbacks Handcuff – A.J. Puk, ARI (ADP – 258.0)
The Marlins gave Puk four starts to open last season, leading to disastrous results (14 runs, 36 baserunners, and 12 strikeouts over 13.2 innings). Miami quickly placed him on the injured list for 23 days with a left shoulder issue. He struggled over his first 14 games in the bullpen (4.61 ERA, 1.171 WHIP, and two home runs over 13.2 innings). Puk became an elite reliever over his next 43.2 innings (one run, 24 baserunners, 68 strikeouts, and four wins), but he gave up the lead in two of four save situations. His season ended with a bad outing (three runs and three baserunners over two-thirds of an inning).
Over his hot streak, Puk had a sensational walk rate (1.6) with an electric rise in his strikeout rate (14.0 – 41.8% for the year). He has a 3.16 ERA, 1.096 WHIP, and 259 strikeouts over his 205.1 career innings as a reliever.
His average fastball (95.7) was down slightly. Puk threw a high-volume slider (.180 BAA) while featuring a four-seamer (.156 BAA) and sinker (.286 BAA). Batters only had seven barrels against him, compared to 15 in 2022 and 12 in 2023.
Fantasy Outlook: The finish by Puk last year screams closing opportunity, but he may have to wait for Justin Martinez to trip up in the ninth inning. His first-pitch strike rate (66) was a career-best, and Puk has 22 saves over the past three seasons. He's a tempting cheat closing option, but his ADP has a better feel in 10 and 12-team formats. If the Diamondbacks name Martinez as the closer in spring training, Puk should slide in drafts, creating a better buying opportunity.
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With 20+ years of experience in the high-stakes fantasy market, I aim to research and compete at the highest level in baseball and football each season. I've contributed as a writer/analyst for Sports Draft Daily, ScoutPro, Scout Fantasy, Fulltime Fantasy, FFToolbox, and Sports Illustrated Fantasy. I'm honored to be in the National Fantasy Baseball Championship Hall of Fame. My drafting philosophy is risk-averse yet open to betting on potential game-changers. I approach player selection with a neutral perspective, acknowledging that fantasy sports are inherently unpredictable due to injuries, performance dips, and managerial decisions. My work focuses on these main areas: - Season-long fantasy baseball and football - BestBall Baseball and Football Events - Daily Fantasy Sports (DFS): DraftKings, FanDuel, and Underdog - Long Shot Player Prop Parlays for NFL I participate in various leagues and contests, including NFBC, NFFC, RTSports, FFPC, DraftKings, Underdog Fantasy, FanDuel, and FFWC, with the goal of leveraging my extensive experience and research for success in each game format. A fantasy follower can expect in-depth profiles of NFL and MLB players, along with season-long and weekly projections for each fantasy football season. In addition, I have many strategy articles to help develop fantasy players' learning curves.