The Cardinals’ offseason trade of Nolan Arenado to the Diamondbacks is looking like a deal both teams can defend and question at the same time. St. Louis sent the 10-time Gold Glove Award winner and significant cash to Arizona for 23-year-old right-hander Jack Martinez, and the early returns have been uneven on both sides.
Arenado is hitting.206/.215/.317 with two home runs and nine RBIs in Arizona, while Martinez is in Class-A Palm Beach with a 1.29 ERA in two starts. The Cardinals were 10-8 when the trade came back into focus, and the Diamondbacks were 11-8, leaving each club above.500 but still watching the move through a different lens than they did in the offseason.
The dollars mattered as much as the player exchange. Arizona received Arenado and $31 million toward his contract, a package that was supposed to give the Diamondbacks more certainty at third base while easing the Cardinals’ payroll burden. Instead, the trade has become part of a larger evaluation of how each club handles the position now and what kind of value it can extract from the move over time.
For St. Louis, the answer has started with Nolan Gorman. He has taken over a larger role at third base and is hitting.208/.290/.321 with two home runs and nine RBIs, while ranking in the 91st percentile in outs above average. That defensive metric sits in sharp contrast with Arenado, who is in the 15th percentile and has minus-1 outs above average this season in Arizona.
The Cardinals had also recently broken down their Willson Contreras, Sonny Gray and Brendan Donovan deals, a sign that the club has been willing to adjust quickly around its core. Trading Arenado fit that pattern, opening third base and freeing up cash while shifting pressure to younger players and a lighter pitching return to prove itself.
That is why the deal still feels unfinished. Martinez has only two starts at Palm Beach, and Arenado’s bat has yet to catch up to his reputation in Arizona. The Cardinals got the flexibility they wanted, the Diamondbacks got the star they were seeking, and both teams now have to live with the part of the trade that cannot be measured yet.