Diamondbacks Acquire Nolan Arenado from Cardinals

The Arizona Diamondbacks acquired eight-time All-Star third baseman Nolan Arenado in a trade with the St. Louis Cardinals on Tuesday, per ESPN’s Jeff Passan.

The Cardinals received right-handed pitcher Jack Martinez, a 2025 eighth-round draft pick from Arizona State.

In the 2025 college season, he recorded a 5.47 ERA across 77 1/3 innings. Arenado, 34, has five Silver Slugger, six Platinum Gloves, and 10 Gold Glove awards, and plays a position of need for the Diamondbacks.

The Diamondbacks will receive $31 million from St. Louis in addition to the infielder to help finance the contract.

Arenado has two years remaining on his nine-year, $275 million contract originally signed in 2019 with the Colorado Rockies. The D-Backs will only responsible to pay him $11 million over the next two years.

Why This Trade Makes Sense for the D-Backs?

The Diamondbacks haven’t had a star at third base, seemingly the role they want Arenado to fill, since just before last season’s trade deadline when two-time All-Star third baseman Eugenio Suarez was traded to his former team, the Seattle Mariners.

He left in exchange for first baseman Tyler Locklear and right-handed pitchers Hunter Cranton and Juan Burgos, leaving behind a big hole at the hot corner.

The D-Backs were reportedly in talks to try to sign free agent Alex Bregman, but after his signing with the Chicago Cubs, Arizona pivoted their efforts to acquiring Arenado.

Given that the trade talks have reportedly been put to rest on Ketel Marte after months of rumors, according to Diamondbacks General Manager Mike Hazen, suddenly Arizona’s infield has a lot of star power.

Especially with Geraldo Perdomo at shortstop, who ended 2025 with a 7.0 bWAR, .290/.389/.462 slash line, and .851 OPS (36 percent above league average), their infield is offensively and defensively equipped to compete against other NL West talent.

Still, as badly as the Diamondbacks may want a stud at third base, Arenado may no longer play like his award-winning self, leaving the team’s needs unsatisfied.

In 2025, he slashed .237/.289/.377 for his lowest slash line of his career, and a .666 OPS (13 percent below league average). He hasn’t recorded an OPS that low since 2020. He also had an 84 WRC+ and 0.9 WAR last season, making him less of an offensive weapon and bringing him dangerously low to replacement level. 

If the D-Backs picked up the whole salary, it would be tough to meet expectations, but at only $11 million over the next two years, Arenado just has to provided strong defense and a stable bat and Arizona will be getting enough production for what they are paying for.

Why This is the Right Deal for the Cardinals

On the Cardinals front, the addition of Martinez adds to an active offseason of bolstering the the Cardinals pitching depth, which President of Baseball Operations Chaim Blum announced was a goal for the 2026 offseason.

They’ve begun doing so, ironically with much of the arm help coming from Blum’s former employer: the Boston Red Sox.

Thus far, the Cardinals traded right-handed pitcher Sonny Gray in exchange for left-handed pitcher Brandon Clarke and right-handed pitcher Richard Fitts; sent first baseman Willson Contreras to the Red Sox for right-handed pitchers Hunter Dobbins, Yhoiker Fajardo, and Blake Aita; and signed right-handed free agent Dustin May, an arm that the Red Sox acquired minutes before the 2025 trade deadline but neglected to re-sign after completing 2025 with a -0.6 bWAR.

Currently, the Cardinals rotation has right-handed pitchers Andre Pallante, May, Michael McGreevy, Dobbins, Kyle Leahy, and Fitts, as well as left-hander Matthew Liberatore.

Contrastingly, the bullpen has JoJo Romero, Riley O’Brien, Matt Svanson, Ryan Fernandez, Justin Bruihl, Gordon Graceffo, and Chris Roycroft.

For a team who ranked 24th and 29th in team WHIP and ERA respectively in 2025, this collection of younger arms creates a clean slate – evidently a priority for Blum who is sacrificing veteran infielders and arms to create a younger rotation for future success.

By clearing Arenado, not only do the Cardinals add an arm, they also clear playing time for their other young infielders, with top prospect JJ Wetherholt being a candidate to break camp in spring training.

Arenado had been in trade rumors for over a year now, which is why moving on was worth sending $31 million the other way.