Justin Martinez Begins Bullpen Work as Diamondbacks Ramp Up Rehab

Arizona Diamondbacks reliever Justin Martinez took a big step in his comeback from Tommy John surgery. On Friday, he threw his first bullpen off a mound.

Manager Torey Lovullo called the session “electric.” Martinez reportedly hit 96-99 mph and even flashed a triple-digit fastball, mixing in a splitter and a slider.

This is just the beginning of a long rehab. He needs to complete 15 bullpen sessions before moving forward, so he’s still several weeks away from returning.

Martinez, just 24, had a stellar 2024-25 season. He saved 13 games for Arizona and posted a 2.76 ERA.

The team’s belief in his late-inning impact only grew after he signed an extension in spring training 2025, right before the injury.

Road to Return: Martinez’s Rehab Milestones

As Martinez inches closer to a full return, the Diamondbacks are trying to stay optimistic but careful. They’re also keeping tabs on a group of other rehabbing players.

Lovullo’s Friday update focused on Martinez’s progress. He also mentioned how the club plans to build bullpen depth and lineup flexibility while waiting for guys to get healthy.

Martinez’s Electric Bullpen Session: What It Means

Justin Martinez threw what Lovullo called an electric bullpen, which is a great sign for his arm after last year’s surgery. The radar gun showed high 90s, sometimes even hitting triple digits—so the fastball’s still got life.

He’s got to get through 15 bullpen sessions before any live action. The velocity and his feel for his pitches are good signs for Arizona’s relief corps as they plan his return to a high-leverage role.

Martinez’s 2024-25 stats—13 saves and a 2.76 ERA—show why the D-backs are being cautious. That extension he signed in spring 2025? It says a lot about how much the team trusts him to anchor the late innings once he’s fully cleared.

Next up: Martinez will slowly ramp up intensity, distance, and workload during bullpen days. He’ll eventually move into simulated games and, if all goes well, real-inning appearances.

For Lovullo and the team, every bullpen session gives them more info about his timeline. But let’s be honest, rehabbing pitchers from Tommy John surgery is never totally predictable.

Rehab Roundup: Other Diamondbacks Updates

• A.J. Puk and Corbin Burnes kept working out of the bullpen Friday at Chase Field. Puk looks on track for a June return, while Burnes is eyeing the All-Star break as he ramps up as a starter following internal brace procedures.
• Ketel Marte jumped back into the leadoff spot against right-hander Clay Holmes after missing Friday’s game with an illness. Lovullo made some lineup tweaks to try and spark more production.
• Geraldo Perdomo slid into the leadoff role earlier this season. He went 0-for-5 Friday, and Lovullo noted he might be pressing at the plate.
• Carlos Santana will get a few more rehab games at Triple-A Reno before the team decides what’s next. He’s 2-for-19 so far in five games there.
• Jordan Lawlar is set for more imaging next week on his broken right wrist. He can’t return until early June, so his big-league debut gets pushed back again.
• Kayson Cunningham, a shortstop prospect, has entered concussion protocol but should be back soon. He’s been hitting .394 in Single-A Visalia, so his timeline is still promising even if it’s a bit unclear.
• Tyler Locklear recently came off the injured list after elbow and shoulder surgeries. The team optioned him to Reno, where he’s gone 4-for-7 with a homer and a ground-rule double while getting more at-bats and defensive work.

 
Here is the source article for this story: Diamondbacks’ Justin Martinez begins throwing bullpens