Report: Justin Martinez Agrees to Extension With Diamondbacks

The D-backs' flamethrowing righty reliever cashes in.

Arizona Diamondbacks pitcher Justin Martinez during spring training workouts at Salt River Fields at Talking Stick on Feb. 14, 2025, in Scottsdale. / Rob Schumacher/The Republic / USA TODAY NETWORK via Imagn Images

According to a report from Moises Fabian and Mike Rodriguez on X/Twitter, the Arizona Diamondbacks and reliever Justin Martinez have reached an agreement on an extension. The report was later confirmed by Arizona Sports 98.7's John Gambadoro.

Pending a physical, the deal is for five years, worth $18 million, and will buy out two years of Martinez's arbitration. According to Fabian, the deal also includes sixth- and seventh-year club options, worth seven and nine million respectively for 2030 and 2031.

Since his first taste of MLB action in 2023, Martinez has been on a steady upward trajectory. The young righty's electric, triple-digit fastball and devastating arsenal of breaking pitches instantly put fans on notice, as he's developed into a serious weapon out of Arizona's bullpen.

He took over closing duties briefly in 2024, but was never named the official closer. Still, he put forward an impressive campaign, pitching 72.2 innings, and posting a 2.48 ERA and 2.59 FIP in those opportunities. He was 8-for-10 in save opportunities.

While he did struggle a bit with the command of his elite arsenal, walking 4.46 batters per nine innings, he also struck batters out at a high clip, with 11.27 strikeouts per nine, or a 29.5% K rate.

Ahead of 2025, the D-backs have opted to go with matchup-based ninth-inning solutions, but it's expected that Martinez will likely get his fair share of save chances.

If he continues to perform well, it would be a surprise to not see him take more of the closer's role, barring any unexpected additions to Arizona's bullpen.

Still just 23 years old, the sky remains the limit for the fireballer. As long as he can stay healthy, and continue to improve the command of his pitches, he'll be a terrifying matchup for even some of the most talented MLB hitters in the coming years.

The future looks bright for the Diamondbacks' bullpen, and Martinez will undoubtedly be a major part of it going forward. This team-friendly extension provides him a financial windfall, while allowing Arizona to lock him into their late-inning plans for years to come.

As this is a developing story, Diamondbacks On SI will continue to report on it as new information is released.