Arizona Diamondbacks draft Oklahoma RHP LJ Mercurius in 2026 MLB Draft

Arizona Diamondbacks drafted Oklahoma right-hander LJ Mercurius in the 2026 MLB Draft on July 14.

What happened?

The Arizona Diamondbacks selected Oklahoma RHP LJ Mercurius in the 2026 MLB Draft. The club added the 21-year-old righty with a mid-90s fastball and a developing slider. Mercurius went 12-2 with a 2.41 ERA and 142 strikeouts in 104 innings for Oklahoma this season.

The Diamondbacks sit 9th in the National League with a 49-47 record. They’ve won four straight games heading into the break.

Why it matters for Arizona Diamondbacks

Mercurius slots into a farm system that already features high-upside arms like Brandon Skenes and Blake Walston. The Diamondbacks need rotation depth after trading Zac Gallen at the deadline. A polished college arm like Mercurius could move quickly through the minors.

Arizona beat the Dodgers 3-5 on July 12. They’re now 49-47 and chasing a wild-card spot. Every arm counts when the bullpen ERA sits at 3.89.

What comes next?

Mercurius will report to Arizona’s Arizona Complex League affiliate in August. The Diamondbacks will monitor his workload after a heavy college season. First-year pros often debut in the ACL in late summer.

The club’s next move could come at the trade deadline. Arizona needs starting pitching to push for October. Mercurius adds another option to a crowded pipeline of young arms.