The Arizona Diamondbacks could be massive sellers at the MLB trade deadline. They have multiple players on expiring contracts as their playoff odds decline by the day. One trade candidate is Zac Gallen, the starting pitcher who helped them reach the 2023 World Series. But Diamondbacks GM Mike Hazen told a trade deadline story that nearly landed him Manny Machado, but would have prevented Gallen from ever coming to Arizona.

“We tried to get Manny Machado from the Orioles in 2018, and Jazz Chisholm would have been in that trade,” Hazen told ESPN's Jesse Rogers. “We didn't trade Jazz there, but that got us Zac Gallen in 2019. We don't get Gallen if we make that trade for Machado, so you never know.”

Chisholm was the Diamondbacks' third-ranked prospect, according to MLB.com, in the 2018 season. Machado was a rental at that deadline, leaving the Dodgers for the San Diego Padres. Trading Chisholm for Machado makes no guarantee that he stays in free agency that winter. Gallen had five years of control when they made that trade.

The most significant “what if” from this trade is the 2018 postseason. LA made the World Series, but lost to an 108-win Boston Red Sox team. The Diamondbacks were in first place on July 31 that year, but Machado sent the Dodgers flying past them. They missed the dance at 82-80, finishing 22-30 down the stretch.

Machado hit 13 homers in 66 games with the Dodgers, but posted a measly .672 OPS in the postseason. The Diamondbacks made the Gallen trade during the 2019 season, but they still missed the postseason. He has finished top ten in Cy Young voting three times as a Snake.

The Diamondbacks could close the circle at this MLB trade deadline by dealing Gallen. He hits unrestricted free agency after this season, which has been poor so far on a struggling team.