The Chicago Cubs’ depth chart on FanGraphs lists Justin Steele, Jameson Taillon, Shota Imanaga, Matthew Boyd, and Ben Brown as the top five in the starting rotation to begin the 2025 MLB season. Noticeably, there are more question marks than answers surrounding the rotation. Can Imanaga duplicate the success he had in 2024 in 2025? Is Brown a reliable candidate until Javier Assad returns from the injured list? Are the Cubs one piece away from having one of the best National League and MLB pitching rotations?

What if the missing piece was Arizona Diamondbacks righty Zac Gallen? Gallen is no longer Arizona’s ace after the club signed Corbin Burnes to a six-year, $210 million contract in December. Even though the Diamondbacks will be without lefty Jordan Montgomery in 2025 because of Tommy John Surgery, Gallen is an impending free agent, and it might be worth dangling his name in trade discussions at the deadline.

Gallen is a one-time All-Star and perennial NL Cy Young Award contender, so his price tag may not be cheap. The Diamondbacks may seek one top-10 prospect and one to two MLB-ready level players in a trade with the Cubs. Chicago Cubs Receive: RHP Zac Gallen

Arizona Diamondbacks Recieve: The Cubs’ No. 6 ranked prospect, outfielder Kevin Alcantara, RHP Ben Brown, and RHP Connor Noland The Cubs’ upside in this deal is obvious. If they are still in the mix to win the NL Central Division title by the deadline, adding Gallen can help them win and advance deep into the postseason. Maybe there are mutual feelings at the season’s end, and Gallen re-signs in free agency.

The Diamondbacks add a top 100 MLB prospect in Alcantara, who offers a unique combination of size and speed in the outfield. He’s shown flashes of power, too, hitting 14 combined home runs in 111 games at Double-A Tennessee and Triple-A Iowa in 2024.

Even without Montgomery, Arizona may be able to afford to lose Gallen. They would also benefit from full and bounce-back seasons from Merrill Kelly and Eduardo Rodriguez. Brown could also slot into the Diamondbacks’ rotation or bullpen this year, as he posted an ERA+ of 112 in 55.1 innings in 2024.

Trading Gallen may not be the Diamondbacks’ plan, but they could consider it if they sense he might not re-sign during the winter and a team like the Cubs makes them an offer they cannot refuse.