Arizona Diamondbacks Hit with Huge Major Update

A Realistic Look at the Diamondbacks’ Bullpen Construction in 2025

As the 2025 season drags on with yet another round of bullpen breakdowns, it’s time to take a closer look at the root causes and the history behind the Arizona Diamondbacks’ ongoing bullpen struggles.

On the evening of the most recent game at Chase Field, the Diamondbacks found themselves in a familiar situation. After fighting their way back from an 8-3 deficit to take an 11-8 lead over the Los Angeles Dodgers, their hopes for a win once again evaporated in the ninth inning. Kevin Ginkel and Ryan Thompson combined to give up six runs, leading to a 14-11 loss.

This collapse was reminiscent of a similar one on April 18 in Chicago. After mounting a comeback from a 7-1 deficit against the Cubs and scoring 10 runs in the eighth inning, the bullpen imploded, allowing six runs in the bottom of the frame. The Diamondbacks ultimately lost 13-11, with struggling relievers Joe Mantiply and Bryce Jarvis sent down to Reno the next day.

The bullpen’s issues were hardly a fluke. From April 19 to May 8, the relief staff posted a 4.69 ERA and an even worse 5.32 FIP, indicating that the problem wasn’t just bad luck.

Heading into the offseason, General Manager Mike Hazen repeatedly stated his intention to strengthen the bullpen, ideally adding a back-end, high-leverage reliever. However, efforts to trade for or sign such a player fell through, and resources were allocated elsewhere, including a six-year, $210 million contract for starting pitcher Corbin Burnes.

That said, the Diamondbacks did make some moves to improve the bullpen. Hazen signed Kendall Graveman, a reliable reliever who had posted a 2.74 ERA over 187 innings between 2021 and 2023. However, Graveman came with injury concerns and missed the entire 2024 season due to shoulder surgery. He signed a one-year, $5 million deal, and after struggling with a back strain in camp, he has just completed rehab games with the Reno Aces and is expected to return soon.

The Diamondbacks also added Shelby Miller on a minor league contract. Miller impressed in spring training, earned a spot on the Opening Day roster, and has been one of the team’s best pitchers so far, posting a 1.08 ERA in 16 appearances. However, Miller was never intended to be the closer.

Additionally, they signed left-hander Jalen Beeks to a one-year deal in late March. Beeks has been a steady presence in the bullpen, throwing 21.2 innings with a 2.08 ERA.

By the time the season began, the Diamondbacks had A.J. Puk and Justin Martinez as their co-closers, and for the first three weeks, things were going well. Together, they combined for six saves and five holds without blowing a lead. However, Puk was sidelined with a flexor tendon strain and is now on the 60-day IL, with a possible return in mid-June. Martinez, dealing with a dead arm and significant velocity loss, is also on the IL.

Ginkel, who had his own injury setbacks in Spring Training, returned in late April but has been shaky, allowing runs in three of his first five outings. During Friday’s meltdown, Ginkel’s velocity was down, and his breaking pitches lacked sharpness, leading to a quick four-run deficit.

Meanwhile, Ryan Thompson, once a reliable sidewinder, has regressed. After allowing just three home runs in 91 innings from 2023 to 2024 (including the postseason), he has already given up three homers in just 15.2 innings this year. Thompson currently holds a 5.74 ERA and a 5.02 FIP.

Had it not been for the strong performances from Miller and Beeks, the bullpen would likely be in an even worse situation. The depth simply isn’t there to withstand the injuries to Puk, Martinez, Ginkel, and Graveman.

One major factor contributing to these struggles is the reluctance to spend significant money on a high-leverage reliever. While several options were available in free agency, the Diamondbacks were unable to compete for any of them. Below is a comparison of some potential bullpen targets, their ages, contracts, and performances to date:

• The Dodgers secured three relievers, including Blake Treinen (who is now on the 60-day IL) and Kirby Yates, who has been used in a setup role thanks to the presence of Tanner Scott.

• The Red Sox, meanwhile, signed both Aroldis Chapman and Kenley Jansen, who have been perfect in save opportunities so far this season.

• Carlos Estevez and Jeff Hoffman have also been solid for their respective teams at relatively low costs.

In the end, the Diamondbacks’ bullpen issues appear to be a result of a combination of factors: bad luck, injuries, and a lack of investment in the back-end of the relief corps. Without more depth and consistent production, these bullpen collapses could continue to haunt the team throughout the season.