News dropped out of the desert on Tuesday that third baseman Nolan Arenado is on his way to the Snakes after waiving his no-trade clause with the St. Louis Cardinals. It signals further commitment to a rebuild for St. Louis shows the Arizona Diamondbacks desire to compete in 2026.
The full details of the trade are:
Diamondbacks receive: 3B Nolan Arenado, $31M cash
Cardinals receive: RHP Jack Martinez (unranked prospect)
Why Arizona made this trade
We’ll look at the trade from both sides, starting with Arizona.
It was reported that the Diamondbacks were trying to sign free agent 3B Alex Bregman before the Cubs got him to ink a 5-year, $175M offer instead (read my analysis on that deal here). Without a great fallback option on the free agent market, they looked to the trade market.
Arenado has been a player on the trade rumor mill for quite some time now, and was actually part of an agreed-upon trade to the Houston Astros last year before he vetoed it with his no-trade clause. One of the factors working against a potential Arenado move (outside of that no-trade clause) was the money owed to him. Whatever team was going to acquire him wasn’t going to be too keen to pay the rest of the $42M left on his contract over the next 2 years. As a result, one wrinkle of negotiations was how much money was going to be packaged with him to make him a more attractive trade candidate. The two sides eventually agreed that Arizona will be responsible for $11M of the $42M remaining, with St. Louis covering the rest (that’s why the $31M comes to Arizona). The Colorado Rockies, who originally traded Arenado to St. Louis, are still covering $5M of that contract themselves, so St. Louis is on the hook for $26M. Now that that’s out of the way, let’s talk baseball.
Because they fell out of the running with Bregman, the D-Backs were forced to pivot. As a younger squad, they wanted a veteran guy who can lead, and Nolan Arenado fits that bill.
Arenado was one of the best players in all of baseball from 2015-2019. In those five seasons, he was 4th in hits (906), 4th in doubles (190), 2nd in home runs (199) and 1st in RBI (621). In Baseball-Reference’s WAR, he trailed just Mike Trout and Mookie Betts in that time frame. He had a fantastic 2022 season (his 2nd season w/ STL), finishing 3rd in NL MVP voting, but has been below his standards since. He was an All-Star in 2023, thanks to his strong first half, but fell off the map post-All Star break.
This past season, 2025, Arenado posted career lows in AVG (.237), OBP (.289), SLG (.377) and OPS (.666). FanGraphs had him at an 84 wRC+, 16% below league average (100 wRC+ is league average). The Diamondbacks are hoping that his bat bounces back to at least league average.
What hasn’t slumped like the bat is the defensive ability. A 10-time Gold Glove winner, Arenado is touted as one of the greatest defensive third basemen in baseball history. Even at the age of 34, he posted +3 Outs Above Average (OAA) in 2025, good for 9th among 3B in baseball. The Diamondbacks are solidifying the left side of their infield with Arenado and shortstop Geraldo Perdomo, who posted +5 OAA in 2025.
The Diamondbacks brought up their top prospect, Jordan Lawlar, this season to play some third base, but with the addition of Arenado, he may be asked to get some work in the outfield for lack of an infield opening. Lawlar struggled in a small sample size of plate appearances in 2025. With Arenado, the Diamondbacks are getting a more trustworthy option to hold down the hot corner.
My take: What’s the downside for Arizona? $5M in 2025 and $6M in 2026 is a small price to pay for what Arenado will bring both on and off the field. You can pencil in some above-average defense at 3B, while betting on his leadership ability to have some sort of effect on the young Arizona roster. The aforementioned Lawlar struggled in more ways than one in 2025… is there a chance Arenado can help the kid out? Little details like that lead me to think that Arizona is playing a safe bet here. I’ll anticipate the D-Backs to make a few more signings, likely in the rotation and bullpen, but I believe they believe they’ll contend this season.
Why St. Louis made this trade
Arenado marks the third veteran sent off the Cardinals’ roster this offseason. Sonny Gray and Willson Contreras were sent to Boston, along with money to help pay for their contracts, similar to what’s happening here with Arenado – that’s $59M the Cardinals are sending to other teams for players not on their own payroll over the next two seasons. Teams tend to go this route when they want to launch a transition to the next wave of talent. The Cardinals are opening up playing time for younger prospects (including their #1 prospect, INF J.J. Wetherholt) they’d like to get acclimated to the majors before they make their next big push for the playoffs and World Series.
In return, the Cardinals get a pitching prospect that hasn’t thrown a professional pitch since being drafted in 2025. A former D-III pitcher, the 6’4” Jack Martinez transferred to the Arizona State Sun Devils for his senior year, when he pitched to a 5.47 ERA, despite a 32.3% K% and fastball capable of some heat.
My take: The Cardinals didn’t have many options at their disposal. Not many teams wanted to take on a veteran that has been on the downward trend in Arenado, unless there was significant money coming with him to cover his contract. Being able to get him out of the building to a place of his approval (Arenado waived his no-trade clause) and get back a big arm with some potential is a good move by St. Louis. Of course, time will tell if Martinez even makes it close to the MLB, but both sides can be happy with this trade.
I will be keeping an eye on what the rumor mill says about Cardinals 2B Brendan Donovan. The 28-year-old Donovan is entering his final year before he hits free agency, and is coming off an All-Star 2025 in which he hit .287/.353/.422 (119 OPS+). He’s a good bat that doesn’t strike out often (13.0%, 92nd percentile) and plays a decent second base. Since his rookie season in 2022, he’s +2 Outs Above Average at that position, though he’s played just about all over the diamond and outfield since 2022. If the Cardinals are waving the white flag and looking to 2027 and beyond, it may be in their best interest to try to shop Donovan, instead of letting him walk in free agency.
Inner Half 