The Colorado Rockies made a bold, calculated move in this year’s Rule 5 Draft, grabbing right-hander RJ Petit with the first overall pick-and it’s easy to see why. At 6-foot-8 and 300 pounds, Petit brings more than just size to the mound. He brings a power-packed arsenal that could be exactly what Colorado’s struggling pitching staff needs.
Let’s start with the numbers. Petit, 26, turned heads in 2025 with a combined 2.44 ERA over 66.1 innings between Double-A Erie and Triple-A Toledo.
He struck out 79, walked just 22, and posted a sharp 1.06 WHIP. Those are the kind of stats that don’t just get you noticed-they get you picked first overall in the Rule 5 Draft.
The Rockies newest Rule 5 Draft pick RJ Petit is an absolute mountain of a man.
— Christian Saez🎙 (@DNVRSaez) December 10, 2025
6’8 300 lbs. pic.twitter.com/4jtkSljQGH
Petit’s breakout year is even more impressive when you consider he wasn’t selected in the 2024 Rule 5 Draft. But this time around, he was one of the most compelling arms available.
His Triple-A performance in particular stood out: a 2.74 ERA and a 34.4% strikeout rate over 23 innings. Those numbers are more than solid-they’re the kind of indicators that suggest he's ready to contribute right now.
And that’s exactly what the Rockies are counting on. Under Rule 5 rules, Petit has to stay on Colorado’s active roster for the entire 2026 season or be offered back to Detroit for $50,000.
That’s not the kind of risk you take on a developmental project. This is a bullpen piece the Rockies believe can help immediately.
What makes Petit so effective? It starts with his slider-a pitch he throws more than 40% of the time.
It’s a tight, two-plane breaker that sits around 83.7 mph and generated a 41.7% whiff rate at Triple-A. That’s a swing-and-miss pitch, plain and simple.
Here are more of my thoughts on RJ Petit https://t.co/jXxFnUu7TC pic.twitter.com/FvhbksIHeu
— Thomas Nestico (@TJStats) December 10, 2025
According to pitch analyst Thomas Nestico, Petit consistently locates it low and away, forcing hitters to chase and miss.
But the slider doesn’t work in isolation. It plays beautifully off his four-seam fastball, which comes in at 95 mph.
That 11-mph velocity gap creates real problems for hitters trying to time him up. Add in his towering frame, which creates a steep downhill angle, and you’ve got a fastball-slider combo that’s tough to square up.
His heater alone drew a 33.3% whiff rate at Triple-A, a testament to how deceptive his release and angle are.
What really elevated Petit in 2025, though, was the development of his changeup. It gave him a third pitch-and a much-needed weapon against opposite-handed hitters.
He threw it at 87.7 mph with above-average strike command, turning himself from a two-pitch power reliever into a more complete arm. That evolution is likely what pushed him from overlooked in 2024 to Rule 5 headliner in 2025.
The results back it all up. Petit finished the season with a 30.1% whiff rate and a 64.6% strike rate.
He wasn’t just missing bats-he was attacking the zone. His 2.94 FIP suggests this wasn’t smoke and mirrors, either.
It’s sustainable performance, not a flash in the pan.
And for the Rockies, that’s huge. Colorado’s pitching staff was a mess in 2025.
The rotation ERA? A league-worst 6.65-nearly a run and a half worse than the next team.
The bullpen didn’t fare much better, finishing with a 5.18 ERA. They desperately need arms who can get outs without relying on Coors Field defense or altitude luck.
Petit fits that need.
His physical profile also helps mitigate some of the challenges of pitching in Denver. With his size and downhill delivery, he naturally creates a plane that keeps the ball on the ground-critical in a park where fly balls turn into doubles in a hurry. His slider works low in the zone, and that’s where you want to live at Coors.
For a team that won just 43 games last season, this isn’t a franchise-altering move-but it is a step in the right direction. Petit brings real swing-and-miss stuff, a refined three-pitch mix, and a body built to handle the grind.
The Rockies aren’t banking on potential here-they’re banking on performance. And if Petit can carry over what he did in 2025, they might have found a bullpen weapon hiding in plain sight.