The Arizona Diamondbacks may have missed out on the postseason in 2026, but the team still has plenty of reasons to feel optimistic about what lies ahead.
One of the biggest positives from the season came from an unexpected source: veteran third baseman Nolan Arenado.
After spending several seasons with the St. Louis Cardinals, Arenado was traded to Arizona during the offseason in a move that initially raised plenty of questions. Given his age, recent production and the financial commitment attached to his contract, there was no guarantee that the Diamondbacks would get the version of Arenado they hoped for.
Instead, the veteran delivered a strong bounce-back campaign and gave Arizona a major reason to believe the trade could ultimately work in its favor.
Perhaps the most important part of the deal from Arizona’s perspective was the financial arrangement. St. Louis agreed to cover $31 million of the $42 million remaining on Arenado’s contract at the time of the trade. That significantly reduced the financial risk for the Diamondbacks while giving them an opportunity to benefit from a veteran player capable of producing at a high level.
Arenado Provides a Major Rebound
Arenado entered the 2026 season with something to prove.
The six-time Platinum Glove Award winner had experienced one of the most difficult offensive seasons of his career in 2025. In just 107 games, he recorded a career-low 89 OPS+ and accumulated only 1.3 WAR.
Those numbers naturally raised questions about whether the 35-year-old was beginning to decline.
Arizona, however, took a chance on him.
That gamble paid off.
Arenado responded with 30 home runs during the 2026 campaign, marking his first season with at least 30 homers since 2022. He also finished the year with a 122 OPS+, demonstrating that he was still capable of producing significantly above league-average offensive numbers.
His resurgence was particularly encouraging because of the uncertainty surrounding his performance entering the season.
Rather than continuing the downward trend suggested by his 2025 numbers, Arenado showed that he still had plenty left in the tank.
For the Diamondbacks, that made the trade look considerably better by the end of the season.
Arizona Took Advantage of a Low-Risk Opportunity
The financial details of the transaction are arguably one of the biggest reasons Arizona can feel good about the move.
The Diamondbacks did not have to take on the entirety of Arenado’s remaining salary. St. Louis contributed $31 million of the $42 million still owed, leaving Arizona with a substantially smaller financial obligation.
That arrangement allowed the Diamondbacks to acquire an established veteran without taking on the full cost associated with his contract.
Considering Arenado’s production in 2026, the decision looks even more favorable.
The third baseman’s 30 home runs and 122 OPS+ gave Arizona legitimate offensive value, while his reputation and experience added another important dimension to the roster.
It was particularly impressive because Arenado was not necessarily viewed as a player expected to return to his previous All-Star-caliber production.
Instead, he became one of the biggest surprises on Arizona’s roster.
Bleacher Report’s Joel Reuter identified Arenado as the Diamondbacks’ biggest surprise of the 2026 season, highlighting just how dramatically his performance exceeded expectations.
The Cardinals Had Their Own Reason to Make the Deal
From St. Louis’ perspective, the decision was about more than simply trading away a veteran player.
The Cardinals had to consider the direction of their roster, Arenado’s contract and his desire to move on from the organization.
Arenado had reportedly been eager to find a new destination, and the Cardinals eventually facilitated a move that sent him to Arizona.
The decision also allowed St. Louis to receive young talent in return.
Among the players acquired by the Cardinals was right-handed pitcher Jack Martinez, who could eventually become an important piece of the organization’s future.
That possibility means it would be premature to declare the trade an unquestionable loss for St. Louis.
Martinez’s development could ultimately have a major influence on how the deal is remembered.
Still, Arizona currently has the more obvious short-term success story.
The Diamondbacks received immediate production from Arenado, while the Cardinals must wait to see what their young return develops into.
Arenado’s Production Wasn’t Enough to Save Arizona’s Season
Despite his individual success, Arenado could not single-handedly push Arizona into the postseason.
The Diamondbacks ultimately fell short of reaching the playoffs, meaning his impressive season did not translate into a complete team success.
Nevertheless, there were several encouraging developments across the roster.
Corbin Carroll, for example, continued to establish himself as one of baseball’s most dangerous speed threats. He led the majors in triples for the third consecutive season, becoming the first player in MLB history to accomplish that feat.
That achievement, combined with Arenado’s resurgence, gives Arizona multiple reasons to remain optimistic.
The Diamondbacks may not have reached October baseball this year, but they can point to several individual performances as evidence that their roster still has considerable potential.
The $31 Million Difference
The financial structure of the Arenado trade could ultimately prove to be one of the most important elements of the entire transaction.
Arizona did not simply acquire an aging veteran with a significant contract.
Instead, the Diamondbacks obtained Arenado while St. Louis absorbed a large portion of the remaining financial commitment.
That allowed Arizona to benefit from his rebound without assuming the entire financial burden.
If Arenado had struggled again in 2026, the Diamondbacks would have had a much bigger problem on their hands.
Instead, he delivered one of his better offensive seasons in recent years.
The 30 home runs represented a major improvement from his previous campaign, while his 122 OPS+ demonstrated that he remained a productive middle-of-the-order option.
The arrangement therefore gave Arizona a favorable combination: limited financial exposure and potentially significant baseball value.
What Comes Next for Arizona?
The biggest question now is whether Arenado can maintain his 2026 production.
At 35 years old, there is no guarantee that he will repeat the exact numbers next season. Veteran players can experience significant year-to-year fluctuations, particularly as they enter the latter stages of their careers.
However, his performance this year gives Arizona plenty of reason to remain confident.
Arenado has already demonstrated that his disappointing 2025 season may have been an aberration rather than the beginning of a permanent decline.
If he can remain healthy and continue providing power and above-average offensive production, he could become an important part of Arizona’s plans moving forward.
The Diamondbacks will also need to strengthen other areas of the roster if they hope to turn individual success into a postseason appearance.
Arenado’s 30 home runs were impressive, but one player cannot carry an entire team through a 162-game schedule.
The Trade Still Has More to Reveal
It may be tempting to declare Arizona the clear winner after Arenado’s resurgence, but the full story of the trade has not yet been written.
The Cardinals received young talent, including Martinez, and his eventual development could significantly change the long-term evaluation of the transaction.
If Martinez develops into a dependable starting pitcher or a high-impact arm, St. Louis could eventually have a strong argument that it made the right decision.
For now, however, the Diamondbacks have the immediate advantage.
They acquired a veteran who was coming off a difficult season, received significant financial assistance from St. Louis and watched him respond with 30 home runs and a 122 OPS+.
That is a much better outcome than many expected when the deal was completed.
Arizona Has Plenty to Build On
The Diamondbacks’ failure to reach the postseason means the 2026 campaign cannot be considered a complete success.
But the emergence of Arenado as a major contributor gives the organization another reason to look ahead with optimism.
His offensive resurgence was one of the more surprising developments of Arizona’s season, particularly considering the questions surrounding him after his 2025 struggles.
The fact that St. Louis is still responsible for $31 million of the remaining contract makes the situation even more favorable for Arizona.
The Diamondbacks effectively reduced their financial risk while giving themselves an opportunity to benefit from Arenado’s remaining productive years.
Now, the challenge will be turning that individual success into team success.
If Arenado can remain productive, Carroll continues to make history and Arizona addresses the weaknesses that kept it out of the postseason, the Diamondbacks could enter next season with a much stronger roster.
For the moment, though, the evidence points toward Arizona getting the better immediate return from the trade.
The Cardinals may eventually benefit from the prospects and young players they received, but Arenado’s 2026 revival has given the Diamondbacks an early advantage — and St. Louis’ decision to cover $31 million of his remaining salary makes that advantage even more significant.
