SEATTLE -- It was only a matter of time before Andrés Muñoz catapulted to the top of the Mariners’ all-time velocity leaderboard.

Long touted for his triple-digits heat in an almost teasing way -- given that Muñoz was recovering from Tommy John surgery when Seattle acquired him in 2020 -- the right-hander hurled a 102.8 mph heater on Thursday in Chicago that raised eyebrows beyond his own dugout.

It was a ball in a 1-2 count to White Sox left fielder Andrew Vaughn, so it had little consequence. But it marked the fastest pitch thrown by any Mariners hurler since pitch tracking began in 2008 -- and it was also the fastest in MLB this season entering Friday.

“I don't know if I've ever seen anybody throw that hard,” Mariners manager Scott Servais said. “He’s got a bright future ahead of him. As we continue to monitor his workload early in the season, he has a chance to be a huge, huge impact arm for us out of the 'pen.”

Entering Friday, only one other player had thrown a pitch at 102 mph or higher this year -- the Twins’ Jhoan Duran, who stymied the Mariners last week -- and only 37 have reached that velocity in the pitch-tracking era, many of them one-off outliers. Healthy, and with a surgically repaired right elbow, Muñoz has the chance to become one of the Majors’ next big power pitchers in relief.

Yet, it’s not necessarily the heat that’s been Muñoz's biggest weapon early in 2022. Seven of the eight batters that he punched out over his first three outings were on his blossoming slider, all swinging. Muñoz typically dials up his four-seam fastball early in counts to get to two strikes, at which point he unveils the breaking ball that, after extensive work in Spring Training, has more bite and less sweep.

“The combination with the slider and my velo is very important,” Muñoz said through an interpreter. “Now that I’m able to command that slider, it forces the hitters to think about the slider, too, and not just sit and look for fastballs. I’m happy that I’ve been able to mix them up.”

That approach was an adjustment, specifically after Muñoz gave up a mammoth third-deck homer last Saturday to Minnesota's Byron Buxton, who was keenly timing him up in the on-deck circle.

“It had to happen,” Muñoz said. “It was a learning experience. It’s going to teach me that I can’t be challenging guys all the time with fastballs.”

After that home run, Muñoz retired each of the next nine hitters he faced, the last eight via strikeouts.

“He’s gaining confidence as a young player,” Servais said. “He's going to pitch some really big innings for us as the season goes along.”

And a big reason for that will be the ongoing development of the secondary pitch. Muñoz has thrown his slider 28 times, and only one of those has seen contact -- a popout by Minnesota’s Luis Arraez, one of the game’s best contact hitters. Muñoz has a whopping 86.7 percent whiff rate on the pitch. To be sure, we are still in wildly-small-sample-size season, but it’s nonetheless notable.

“I’ve always been one of the hardest throwers among my teammates,” Muñoz said. “But it didn’t matter because I couldn't throw strikes back then. As soon as I started to command the zone is when people started noticing.”

Given that he didn’t return from Tommy John surgery until last Sept. 17 -- and that he pitched only five games before season’s end and had a shortened Spring Training -- Muñoz won’t pitch in back-to-back games in April and instead will be earmarked for roughly three outings per week. And it’s likely those appearances will include more and more leverage.