Scouting Report

Scouting grades: Fastball: 50 | Slider: 50 | Control: 55 | Overall: 40

The selection of Perez as a college senior out of Texas Christian in the 11th round of the 2022 Draft didn’t draw too much attention, and there wasn’t much buzz around him after a solid first full season of pro ball spent mostly at the Single-A level. He suffered through a tough 2024 campaign in High-A, but things started getting a little interesting last year, when he pitched his way from High-A to Double-A. The Mariners didn’t protect him on the 40-man roster, and he went unselected in the Rule 5 Draft.

The 5-foot-10 Perez will never be confused with a flamethrower, but he does have a feel to pitch and for the strike zone. His fastball averaged around 93 mph last year, and he showed the ability to hold his velocity deeper into starts. But whatever success he has, he owes to his sliders. He throws them more than the heater, and he’ll use both a hard, short gyro-like pitch up to 87 mph as well as a low-80s sweeper. He’s tinkered with a variety of changeup grips and styles but hasn’t found one he can command.

Perez continues to be an extreme strike-thrower, carrying a career 2.5 BB/9 rate into the 2026 season. He’ll get the opportunity to keep starting for now, but he’s pitching this year at age 26, so the clock is ticking. With younger starting pitching prospects coming behind him, there could be a time soon where the Mariners put Perez in a bullpen as a slider monster who maybe can gain a few more ticks in velocity in shorter stints.

Scouting grades: Fastball: 50 | Slider: 50 | Control: 60 | Overall: 40

The later rounds of the 2022 Draft could end up being very fruitful for the Mariners. Twelfth-round pick Tyrone Taylor has spent time in the big leagues the past two years, and while Tyler Gough is rehabbing from Tommy John surgery, he’s still a well-regarded pitching prospect who went in Round 9. Perez was a college senior taken in the 11th round who didn’t really register on the prospect radar until this season, when an uptick in velocity has led to better results and enabled him to pitch his way from High-A Everett to Double-A Arkansas.

An undersized right-hander at 5-foot-10, Perez is all about strikes and spin. His fastball has ticked up to averaging around 93 mph. It’s not a difference-maker, but his ability to hold and command his velocity in longer starts has helped him improve. He has two different sliders he throws more than the heater, and both are effective -- a shorter gyro-like breaker at around 87 mph and a low-80s sweeper.

Helping all of his stuff play up is his ability to fill up the strike zone with all of his offerings. His walk rates continue to be very low, even as he climbs the ladder. His ceiling might be limited because of the lack of a true out pitch or above-average heat, but he could pitch his way into a No. 5 starter/swingman role in the big leagues.

Scouting grades: Fastball: 50 | Slider: 50 | Changeup: 40 | Control: 50 | Overall: 40

Perez was selected as a reliever by the Angels in the late rounds of the 2021 Draft but he opted to return to Texas Christian University, then upped his stock to the 11th round, where the Mariners took him one year later and signed him for $125,000. He had a solid debut season in ‘23, making 15 starts at Single-A Modesto before a late-season promotion to High-A Everett. 

Undersized at 5-foot-10, Perez nonetheless possesses athleticism for his build. His fastball sits around 92-93 mph, with good ride and break, which allows it to play up more than the radar gun shows. It’s also possible that he continues to grow into more velocity. It’s the slider that really took off in his first year, particularly the command of the pitch that has good two-plane break. It’s already consistently missing bats in the pros.

Perez has exclusively started in his short stint in the organization, but for him to remain there, he’ll need to fortify at least one more pitch, the clearest offering being the changeup that he’ll drop in occasionally. Even with just a two-pitch mix, there’s a good foundation for him to eventually work as a reliever in the Majors.

Scouting grades: Fastball: 50 | Slider: 50 | Changeup: 40 | Control: 50 | Overall: 40

Perez spent his first three seasons at Texas Christian pitching solely in relief, showing enough for the Angels to take a last-round flier on him in the 2021 Draft. He opted to return to the Horned Frogs in 2022 and again pitched mostly in relief, though some opportunities to start caught the Mariners’ eye, and they took him in the 11th round that July and signed him for $125,000. He had a solid pro debut in 2023 pitching out of Single-A Modesto’s rotation.

While Perez is undersized at 5-foot-10, he’s an athletic right-hander who throws a lot of strikes. His fastball sits around 92-93 mph and features good ride and vertical break, allowing it to play up more than the velocity might indicate. He leans heavily on his mid-80s slider, a pitch that features two-plane break and he commands well, missing a good amount of bats with it.

For Perez to have a chance to keep starting, he’s going to have to greatly improve his changeup, which is currently a distant third pitch. If that doesn’t happen, his fastball-slider combination could allow him to carve out a career as some kind of middle relief/long-man type of role in the big leagues.

Awards

CAL Pitcher of the Week

Week	Team
07/30/2023
06/11/2023

Transactions

Team	Date	Transaction
	03/05/2026	RHP Marcelo Perez assigned to Seattle Mariners Prospects.
	02/22/2026	RHP Marcelo Perez assigned to Seattle Mariners.
	09/22/2025	Arkansas Travelers activated RHP Marcelo Perez from the 7-day injured list.
	09/10/2025	RHP Marcelo Perez assigned to Peoria Javelinas.
	08/24/2025	Arkansas Travelers placed RHP Marcelo Perez on the 7-day injured list.
	06/24/2025	RHP Marcelo Perez assigned to Arkansas Travelers from Everett AquaSox.
	04/30/2025	Everett AquaSox activated RHP Marcelo Perez from the 7-day injured list.
	04/04/2025	Everett AquaSox placed RHP Marcelo Perez on the 7-day injured list.
	03/21/2024	RHP Marcelo Perez assigned to Seattle Mariners Prospects.
	02/07/2024	Seattle Mariners invited non-roster RHP Marcelo Perez to spring training.
	08/22/2023	RHP Marcelo Perez assigned to Everett AquaSox from Modesto Nuts.
	08/22/2023	Everett AquaSox activated RHP Marcelo Perez.
	05/23/2023	Modesto Nuts activated RHP Marcelo Perez from the 7-day injured list.
	05/23/2023	Modesto Nuts activated RHP Marcelo Perez from the 7-day injured list.
	05/05/2023	Modesto Nuts placed RHP Marcelo Perez on the 7-day injured list.
	05/04/2023	RHP Marcelo Perez assigned to Modesto Nuts from ACL Mariners.
	05/04/2023	Modesto Nuts activated RHP Marcelo Perez.
	12/01/2022	RHP Marcelo Perez assigned to ACL Mariners.
	07/26/2022	Seattle Mariners signed RHP Marcelo Perez.
	02/06/2022	TCU Horned Frogs activated RHP Marcelo Perez.
	02/06/2022	RHP Marcelo Perez assigned to TCU Horned Frogs.
	02/06/2022	RHP Marcelo Perez assigned to TCU Horned Frogs.
	02/01/2021	RHP Marcelo Perez assigned to TCU Horned Frogs.
	02/01/2021	RHP Marcelo Perez assigned to TCU Horned Frogs.
	09/30/2019	RHP Marcelo Perez assigned to TCU Horned Frogs.
	02/08/2019	RHP Marcelo Perez assigned to TCU Horned Frogs.