Mariners rookie outfielder Julio Rodríguez has had a lot of eyes on him both in spring training and to start the 2022 regular season, but he’s not the only top Seattle prospect to break camp with the big league club.

The other is Matt Brash, a 23-year-old right-handed pitcher who has had a meteoric rise since joining the Mariners at the 2020 MLB trade deadline.

Jesse Winker on trade to Mariners: “This is where I want to be”

Brash followed up a stellar 2021 minor league season with a dominant spring, which earned him the fifth and final spot in Seattle’s starting rotation. Now, Brash is set to make his MLB debut in the 1:10 p.m. Tuesday afternoon game against the Chicago White Sox, which you can listen to here on Seattle Sports Station 710 AM.

Mariners fans obviously know Marco Gonzales well, got a good look at Chris Flexen and Logan Gilbert last season, and have seen what new ace Robbie Ray can do, but Brash is a bit of an unknown to many at this point. So let’s take a closer look at the rookie hurler ahead of his first career MLB game, shall we?

The bio

Brash stands 6 foot 1 and weighs just over 170 pounds.

The soon-to-be 24 year old (he turns 24 on May 12) was a fourth-round pick of the San Diego Padres in 2019 out of Niagara University in New York.

Brash is Canadian, hailing from Kingston, Ontario.

The Mariners acquired Brash at the 2020 MLB trade deadline from San Diego in exchange for reliever Taylor Williams, who had been serving as Seattle’s closer in the shortened season. Brash wasn’t traded right away, though, as he was actually a “player to be named later” in the deal.

Brash didn’t play at all in 2020 due to the minor league season being canceled amid the COVID-19 pandemic, and before coming to the Mariners he’d appeared in just two minor league games, pitching 5 1/3 total innings and striking out nine batters.

Monster first year with the Mariners

Brash went from a player to be named later in a trade for a little-known reliever to one of the best pitching prospects in baseball in just over a year.

The righty started the 2021 season in High-A Everett alongside many of the Mariners’ other top prospects. He performed very well in 10 games (nine starts), going 3-2 with a 2.55 ERA and 1.32 WHIP over 42 1/3 innings, striking out 62 while walking 25. That equated to a rate of 13.18 strikeouts per nine innings and 5.31 walks per nine.

Brash was then called up to Double-A Arkansas and upped his game against the better competition. In 10 starts, Brash went 3-2 with a 2.13 ERA and even 1.00 WHIP in 55 innings, striking out 80 and walking 23. His strikeouts per nine dipped just barely to 13.08 and he decreased his walks per nine rate down to 3.76.

Matt Brash spins a seven-inning shutout!

The @Mariners' No. 11 prospect flirts with a no-no in his first career complete game for @ARTravs. pic.twitter.com/2KjFRzMMl9

— MLB Pipeline (@MLBPipeline) August 19, 2021

If that sounds like a high strikeout rate, you’d be right. Brash’s 13.1 K/9 rate between High-A and Double-A was higher than any qualified starting pitcher at the MLB level in 2021. Carlos Rodón of the White Sox – now with the San Francisco Giants — led qualified starters with a 13.04 clip. Ray, who won the American League Cy Young and is one of the best strikeout starters in MLB history, was fourth at 12.23.

The stellar run between High-A and Double-A led to Brash being added to Seattle’s MLB roster for the final series of 2021 against the Los Angeles Angels, but he didn’t make his MLB debut.

Brash entered the 2022 season as Baseball America’s No. 46 overall prospect while MLB Pipeline rates him at No. 97 overall. Brash is the Mariners’ No. 4 and No. 6 prospect, per Baseball America and MLB Pipeline, respectively. In the case of Baseball America, Brash is rated even higher than 2020 first-round pick Emerson Hancock.

Winning the No. 5 job

Aside from the signing of Ray – which is a monster addition – the Mariners didn’t address the starting rotation in free agency or trade this offseason, though general manager Jerry Dipoto made it clear that they were looking to add another impact arm if the right opportunity presented itself.

That left the door open for Brash, fellow top pitching prospect George Kirby and Justus Sheffield, who served in Seattle’s rotation at times in each of the past two seasons, for that final spot.

Sheffield didn’t allow a run in spring training over 4 2/3 innings while Kirby posted an ERA over 7 in 7 2/3 innings.

Brash, meanwhile, allowed just three hits and one run over 9 1/3 innings in three games (two starts) while striking out 12 and walking two. Brash had a 0.96 ERA and 0.536 WHIP along with 11.6 strikeouts per nine and just 1.9 walks per nine.

Matt Brash was unhittable today, fanning 6 in 3 scoreless innings for the #Mariners.

Scouting report and more for MLB’s No. 98 prospect: https://t.co/Xko07IpdHp pic.twitter.com/nzJWUYr8K0

— MLB Pipeline (@MLBPipeline) March 27, 2022

That earned him the spot in the Mariners’ rotation.

Scouting report

To have as high of a strikeout rate as Brash did in 2021, you’ve got to have electric stuff. That’s exactly the case with Brash.

Brash possesses four pitches but leans heavily on his fastball and slider. And for good reason. MLB Pipeline grades both pitches at 65 on the 20-80 grading scale, meaning they’re both plus pitches bordering on being “plus-plus.”

Baseball America takes it a step further, grading those two offerings at 70, or “plus-plus.”

Pipeline rates Brash’s other secondaries as well as his control as 50 – or average – while Baseball America gives the changeup an above-average 55 grade and the control a 45 grade, or just below average.

Per Pipeline, Brash’s fastball averaged 96.4 mph last year. Per Statcast, only nine pitchers who threw more than 2,000 pitches at the MLB level in 2021 averaged 96.4 mph or faster on their fastball.

The fastball velocity will certainly be noticeable as soon as Brash takes the hill, but the slider/breaking ball is the showstealer. The pitch will sit in the low- to mid-80s with plenty of sweep that allows Brash to miss plenty of bats.

Matt Brash’s slider is ELITE. #SeaUsRise pic.twitter.com/oiKhISzSk9

— Mariners Player Development (@MsPlayerDev) September 3, 2021

Brash’s go-to breaking ball can be described as either a slider or curve. Regardless, it’s a diabolic breaking ball that can be an absolute hammer, and at times it looks like Brash is throwing a whiffle ball. When Brash was truly on in 2021 – which was often – his stuff was reminiscent of former Chicago Cubs standout hurler Kerry Wood from the late 1990s and early 2000s with his electric fastball and disgusting breaking ball.

According to Baseball America, Brash’s slider/breaker had a whiff rate over 40% as well as a strike rate over 60%. That shows not only that it’s a nasty pitch that can generate plenty of swings and misses but that Brash has pretty good command of it as well. Brash also used it more than any pitch in 2021 at 46% of the time.

When Brash takes the hill Tuesday afternoon against the White Sox, expect plenty of mid- to high-90s fastballs and plenty of hard, sweeping breaking balls as he gets his first taste of MLB action. It will be a good test for Brash as the White Sox won 93 games last year and will once again have one of the best lineups in the AL and MLB as a whole.

The stuff is electric, but as is the case with any pitcher, command will be key for Brash. That’s not just for this first start but going forward. Brash’s stuff almost certainly will play at the big league level, but how well he’s able to command it will dictate whether he can be a long-term starter or a potential high-leverage reliever coming out of the bullpen with two plus pitches.

Regardless, Brash is yet another example of Dipoto acquiring incredible talent for cheap from the Padres.

Mike Lefko: Three things that jump out from Mariners’ start

Follow @TheBGustafson