The case for Mason Miller as the next Padres’ ace. 

After arguably the most chaotic trade deadline in Padres history, the dust has finally settled, and it’s time to examine Mason Miller. As San Diego looks ahead, speculation is already swirling about Miller transitioning into a starting role in the 2026 season.

Miller will pitch in relief, but Preller seemed to leave the door open for him to start in the future: “It’s nice to have 4+ years with Mason Miller. He’s a guy that brings a lot to the table, and we’ll continue to see what’s the best [way] for him to impact the Padres as we go.”

— AJ Cassavell (@AJCassavell) July 31, 2025

The move would make sense. With Dylan Cease likely to depart in free agency after this year, a significant hole in the rotation is looming. That leaves one big question: Can Mason Miller succeed as a starter at the Major League level?

Pitch Mix

This season, Miller has leaned heavily on two pitches: a four-seam fastball and a slider. The fastball is an outlier. It’s thrown at 54.4% of the time and averages 101.1 mph. The pitch generates 17 inches of induced vertical break (iVB) to go along with a spin rate over 2,500 – that’s elite. Miller keeps the fastball at the top of the zone, giving the illusion that the ball is “rising”, which explains the 36.9% whiff rate. 

The equalizer is Miller’s slider. Opponents are hitting just .111 against the pitch and are whiffing 50.8% of the time. Thrown at an average of 88–90 mph with a sharp, late break, the slider pairs perfectly with his fastball. It tunnels well out of the same arm slot, making it nearly impossible for hitters to distinguish the two until it’s too late. This devastating one-two punch gives Miller a high floor and the potential to dominate big league lineups.

103 MPH paint ?
90 MPH filth ?

Mason Miller locks down the save in style! pic.twitter.com/KrIBjKdWGR

— MLB (@MLB) July 13, 2025

Mechanics

Miller has a clean and repeatable delivery, which will serve him well if he makes the transition to the rotation. Why is this important? If he were someone who had a lot of moving parts in the delivery, it could become taxing for him, making it harder to work deeper into games. Because his mechanics involve minimal movement, he conserves more energy with each pitch.

Additionally, his mechanics don’t present any major red flags. His arm path is short and the arm is “on time” when his front foot lands. Once that front foot hits the ground, he fires over his front leg exceptionally well, creating elite extension (76th percentile). These movements limit the amount of strain that is put on both his elbow and shoulder, which is especially encouraging given the usual injury concerns surrounding high-velocity arms.

Previous Experience

When Miller was first called up in 2023, he was initially a starter. In six starts he posted a 3.70 ERA, 1.15 WHIP, 27:11 K:BB across 24.1 innings. The sample size is small for sure, but he showed he can have success. This leaves room for Miller to grow as a starter and the Padres have proven they can develop relievers into high-impact starters. Michael King anyone?

Mason Miller, 101 mph Fastball and 88 mph Slider, Overlay.

That’s not fair. pic.twitter.com/09DbOMYddE

— Rob Friedman (@PitchingNinja) April 17, 2025

Question Marks

Transitioning Miller from the bullpen to the rotation comes with obvious risks — the biggest being his health. The most notable concern surfaced in 2023 when he was diagnosed with a “very mild” UCL sprain. While he’s shown no lingering effects over the past two seasons, durability will always be a concern when ramping up innings and workload.

Another key hurdle is pitch development. Miller has showcased a changeup, but it’s largely a non-factor in his current arsenal. He also experimented with a cutter briefly in 2023, though it was hit hard, opponents batted .429 against it, making it an unreliable option for now. However, it could be a very effective pitch if utilized properly. He most likely will need to add a pitch that moves into righties as well. 

Here’s a clip of Mason Miller’s devastating new “cutter”.

The M’s broadcast interviewed Sam Haggerty, who offered at this demon pitch, in the next half inning: “They told me it was a cutter, but I didn’t even know he threw a cutter. That was…wow.” #RootedInOakland pic.twitter.com/3QSA38id8O

— Uprooted (@uprootedoakland) March 25, 2023

Lastly, command will be crucial. His 11.9% walk rate is high and simply won’t cut it in a starter’s role, especially when trying to work through lineups multiple times. If Miller hopes to consistently pitch five or six innings, sharpening his control and expanding his pitch mix will be essential steps forward. 

Final Thoughts

At the moment, the Padres have added an elite weapon to bolster the “Four Horsemen” and will strengthen their push toward the postseason. As for the future, all signs point to Miller being capable of being a frontline starter for the Padres. Sure, there are risks involved, but name me one pitcher in Major League Baseball who doesn’t carry some injury risk? You won’t find one. 

Picture a rotation headlined with King, Miller, and Nick Pivetta. That gives the Padres plenty of chances to contend for a World Series for years to come. 

Ethan Penrod

Ethan is an aspiring sports analyst that has a passion for all sports. He was a collegiate baseball player and now is finishing up his schooling at San Diego State University. He is a rising senior and a journalism major. Ethan hopes to use his knowledge of sports and display it with his writing.