MLB Mock Blockbuster Trade: Arizona Diamondbacks Deal Zac Gallen to Toronto Blue Jays

Right-handed starter Zac Gallen hasn't been able to get back to his 2023 All-Star level this season for the Arizona Diamondbacks. In fact, until just recently, he was very much headed in the other direction.

But Gallen may be getting back on track just soon enough to do one of two things -- help the Diamondbacks make a push for the playoffs or possess enough trade value to yield a strong return on the market for Arizona.

Gallen made it clear to reporters at the end of last week that he prefers the former option.

"I would like to not be in that discussion," Gallen said about his trade rumors according to USA Today's Bob Nightengale. "I would like for us -- and it starts with me -- to put us in a position where the front office believes this is a team they can add to where we can finish this thing out and see what happens come October."

It's still to be determined whether the Diamondbacks will put that plan into action. Over the past couple weeks, multiple baseball insiders have referred to Arizona as the "most intriguing" and even the "fulcrum" of the 2025 MLB trade deadline. Either way, what the team elects to do will greatly impact the rest of the league at the end of July.

How the Diamondbacks perform over the next three weeks will likely be the biggest determination with the decision.

If Arizona elects to sell, Gallen may be one of its top trade chips. Several teams could use his starting experience, including the surging Toronto Blue Jays.

Let's explore the possibility of Gallen heading north of the border before the trade deadline.

Arizona Diamondbacks-Toronto Blue Jays Mock Trade

Arizona Diamondbacks receive No. 12 Blue Jays prospect Charles McAdoo and No. 19 Blue Jays prospect Ryan Jennings.

Toronto Blue Jays receiver right-hander Zac Gallen.

The Diamondbacks aren't that far away from contention with a 45-46 record entering play on July 8. The team is also only two years removed from a World Series appearance.

With that in mind, I projected Arizona to be most interested in acquiring prospects that were close to the MLB. Before the 2025 regular season, MLB.com projected both McAdoo, a third baseman and outfielder, and Jennings, a right-hander pitcher, to be ready for the Major Leagues by 2026.

Things can change in three weeks, but behind a nine-game winning streak to end June and begin July, the Blue Jays have moved into first place in the AL East. They currently have a 3.5-game lead over the New York Yankees.

If Toronto continues to play well and hold first place, the organization shouldn't have an issue giving up two top 20 prospects for Gallen even though he's a rental player. The Blue Jays haven't been to the World Series in 32 years.

In 2025, Gallen is 7-9 with a 5.15 ERA and 1.345 WHIP. He also has 107 strikeouts in 110 innings. Those statistics don't exactly scream top trade deadline acquisition.

But Gallen has encouraged scouts over his last two starts. He has allowed one earned run on 10 hits with 19 strikeouts and only one walk in his last 13 innings.

"It may be premature to say he’s completely back, but teams scouting him have been impressed, believing that the D-backs will trade him before he hits free agency this winter," wrote Nightengale.

"The irony of Gallen’s success is that the better he pitches, the higher his trade value, but also the better chance that the D-backs keep him since he could get them back in the playoff race."

Whether he stays in Arizona or moves on to Toronto or another place, fantasy managers could really use the 2022-24 Gallen down the stretch. The right-hander went 43-19 with a 3.20 ERA and 9.4 K/9 rate over those three years.

Gallen might have an opportunity for more wins with the Blue Jays than Diamondbacks, but the right-hander can turn around his season for fantasy managers with either team.