The Cardinals traded third baseman Nolan Arenado to Arizona for a pitcher with no professional experience. Jack Martinez pitched in college through his age 22 season and went to the Diamondbacks in the eighth round of the 2025 draft:

Arenado is owed $42 million over the next two seasons, and Arizona will receive $31 million in the deal, a source told MLB.com’s Mark Feinsand, though the present-day impact for the Cardinals comes out to less than that as St. Louis will pay out the $6 million in deferred money owed to Arenado, which isn’t payable until 2040-41.

Arenado had a no-trade clause that he waived for the D-backs.

MLB.com

Martinez doesn’t strike me as an outstanding prospect, although he did get his walks under control as a senior. Arizona had to send a body the Cardinals way, and he was it. Musings Marcels projects Arenado to hit .253/.306/.403 in 2026. Diamondbacks third basemen combined to hit .234/.309/.488 in 2025, so not really an improvement. I suspect Arenado’s power will be higher in 2026 due to the elevation of Phoenix, but a .488 slugging percentage might be a stretch.