In one of the most significant roster moves of the early 2026 offseason, the St. Louis Cardinals have officially traded veteran third baseman Nolan Arenado to the Arizona Diamondbacks in a major league transaction that’s drawing widespread attention across baseball. (Reuters)

The deal, announced by both clubs on January 13, marks the end of Arenado’s five-year tenure in St. Louis. In return, the Cardinals acquired 22-year-old right-handed pitching prospect Jack Martinez, who was selected by Arizona in the eighth round of the 2025 MLB Draft. (Reuters)

Arenado, an eight-time All-Star and 10-time Gold Glove Award winner, waived his no-trade clause to facilitate the transaction, a move that opened the door for the Cardinals to reshape their roster. Though his offensive performance dipped in the 2025 season—with a .237 batting average, 12 home runs and 52 RBIs in 107 games—the 35-year-old remains one of the most decorated defensive third basemen in modern baseball history. (Reuters)

Financially, the deal includes significant cash considerations. The Diamondbacks will cover roughly $11 million of Arenado’s remaining $42 million salary over the next two seasons, while St. Louis absorbs the balance of the financial commitment. The Colorado Rockies, Arenado’s original team prior to his Cardinals acquisition, will also contribute $5 million to his 2026 pay. (ESPN Radio 1430am)

Cardinals president of baseball operations Chaim Bloom released a statement expressing gratitude for Arenado’s contributions both on and off the field. He said, “We are grateful for Nolan’s five years as a Cardinal—his drive, competitiveness, and all the memories he gave us.” Bloom also highlighted the opportunity the trade creates for the team’s younger players to step forward and grow at the major league level. (ESPN Radio 1430am)

Arenado’s legacy in St. Louis includes multiple highlight-reel defensive plays and leadership in the clubhouse. Originally acquired from the Colorado Rockies in 2021, he quickly became a fan favorite for his consistent excellence and passion for the game. Across 13 MLB seasons, Arenado has compiled 1,921 hits, 353 home runs and 1,184 RBIs, helping cement his reputation as one of the premier third basemen of his generation. (ESPN Radio 1430am)

For the Diamondbacks, adding Arenado addresses a key position need and brings veteran presence to a club seeking more consistent offensive output. Despite his struggles in 2025, Arizona believes that Arenado’s elite defense and track record of production can be valuable assets as they prepare for the 2026 campaign. (Reuters)

Meanwhile, the Cardinals’ focus appears to be shifting toward a younger core and long-term rebuilding strategy, underscored by the acquisition of Martinez, a promising arm with developmental upside. As the league moves closer to spring training, this high-profile transaction continues to reverberate throughout baseball circles. (Reuters)

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If you want, I can also write a feature story version with quotes and deeper context on what this means for both teams in 2026.