Kumar Rocker Is Finally Here, Plus Five Overlooked Rookie Hurlers

The former Vanderbilt star may be the Rangers’ next ace after taking a circuitous path to the majors and making an electric MLB debut. Plus, five rookie pitchers flying under the radar amid stellar seasons.

Rocker pitches to the Seattle Mariners during the first inning at T-Mobile Park. / Steven Bisig-Imagn Images

Welcome to the Rookie Roundup, a weekly look-in on baseball’s best and most interesting first-year players. Last week, we showed some love for Milwaukee Brewers phenom Jackson Chourio, who, at age 20, looks like a budding superstar. Next up, it’s time to celebrate the long-awaited arrival of Kumar Rocker to the big leagues.

Everybody knows the story, but the passage of time moves at a relative pace and can impact the ability to reliably recollect various series of events. So let’s take a quick trip down memory lane and wind the clocks all the way back to 2019, when the baseball world was enamored with a certain Vanderbilt freshman named Kumar Rocker.

At the time, Rocker was a 19-year-old flamethrower for the nation’s premier collegiate program. He was already a prospect of note long before he had his coming out party during that year’s NCAA tournament: a 19-strikeout no-hitter in the super regionals that labeled him a future superstar. Rocker went on to win both of his starts in the College World Series as Vanderbilt won the national championship.

All of that made Rocker the Paul Skenes of his era (minus the mustache). But a pandemic-shortened 2020 halted his superstar-bound momentum, and injury concerns caused him to fall to pick No. 10 in the 2021 draft. When he and the New York Mets failed to reach a contract agreement over injury concerns, Rocker went unsigned. He then underwent shoulder surgery and spent the next season in independent ball.

Rocker’s draft stock not only survived the wayward year but actually improved, as the Texas Rangers took him with the third pick in 2022. His ‘23 season lasted only six starts at High A before he was shut down and went under the knife again—this time for Tommy John surgery.

That’s a lifetime’s worth of ups and downs to cram into four years of a promising career. All of that time out of the spotlight might have caused some to forget about Rocker, but the now-24-year-old has recovered from his setbacks and finally made his debut Thursday. And in four electrifying innings, Rocker made up for lost time.

Rocker looked like the ace who was promised all those years ago. He struck out seven of the 17 batters he faced, allowing just one walk and one run on a solo homer. His fastball sat at 97 mph and topped out at 98. He generated a whopping 40% whiff rate on 42 swings—including 13 whiffs out of 21 swings against his devastating slider.

That repertoire—which came from a smooth, free and easy delivery that’s a sight to behold—made opposing Seattle Mariners hitters look silly on several occasions. Feast your eyes on this platter of off-balance cuts and non-competitive swings:

17 whiffs from @KumarRocker last night. 🌬️

The most ever by a Rangers pitcher during his @MLB debut in the pitch-tracking era. pic.twitter.com/qvx2a02lCc

— Texas Rangers (@Rangers) September 13, 2024

The showing was both the culmination of a long road back and perhaps the start of something special. In a middling year from the defending champions, Rocker’s arrival provided a breath of fresh air and tons of optimism for the future. It’s also just the latest in what’s been a year full of dazzling debut seasons on the mound.

Players like Skenes, Yoshinobu Yamamoto and Shōta Imanaga deservedly get much of the hype when it comes to rookie pitchers. But there have been plenty others who have had impressive debuts yet been overlooked for one reason or another—just like Rocker. So with respect to Skenes & Co., here are the top five debut seasons for pitchers that have been overshadowed by the bigger names.

Spencer Arrighetti, Houston Astros

Season stats: 26 GS, 7–12, 4.72 ERA, 158 K

His 4.72 ERA and 7–12 record likely won’t earn him many Rookie of the Year votes. But Arrighetti’s presence in a beleaguered Houston rotation has been vital for the Astros’ second-half surge up the standings, with the team poised to capture its fourth consecutive American League West title.

A sixth-round pick in 2021, Arrighetti has strong stuff, headlined by a mid-90s fastball and devastating curveball. Command has kept him from finding consistency, but he’s rounded into good form of late, logging quality starts in seven of his last 10 outings. He owns a 3.12 ERA with 72 strikeouts in 57 2/3 innings during that span, developing into a reliable starter just when Houston needs him most. With Justin Verlander struggling, Arrighetti will likely be counted on in the postseason behind Houston’s strong trio of Framber Valdez, Hunter Brown and Ronel Blanco.

Myers delivers a pitch against the Colorado Rockies in the first inning at American Family Field. / Michael McLoone-Imagn Images

Tobias Myers, Milwaukee Brewers

Season stats: 24 G (23 GS), 8–5, 3.07 ERA, 1.16 WHIP

After bouncing around six different organizations across nine years in the minors, Myers has thrived after finally getting a chance at the big-league level. He’s the poster child for the Brewers’ band of unsung heroes, and has progressed beyond merely a feel-good story and become a full-blown impact arm.

Myers doesn’t get by on overpowering stuff, but instead finding consistent effectiveness by pitching to contact and limiting free passes. He’s given up two earned runs or fewer in eight of his 10 starts since the All-Star break, highlighted by an 11-strikeout outing on Sept. 7. In a Milwaukee rotation short on household names but deep with reclamation projects, Myers has stood out. His 3.07 ERA ranks third among rookies with at least 100 innings pitched.

Mitchell Parker, Washington Nationals

Season stats: 27 GS, 7–9, 4.24 ERA

The Nationals selected Parker, a junior college prospect, in the fifth and final round of the 2020 draft for a relatively meager $100,000 bonus. He steadily worked his way through Washington’s system without a ton of buzz from the scouting world, so when he made his debut at Dodger Stadium on April 15, his five innings of two-run ball was a pleasant surprise.

Fast forward five months to now, and Parker is wrapping up a strong rookie campaign. His 142 1/3 innings to date are second only to Imanaga among rookies, and his 3.80 FIP backs up his encouraging on-the-surface stats. Following a rough second-half stretch that seemed to indicate hitting a rookie wall, Parker has been sharp of late, posting a 3.38 ERA and 2.50 FIP over his last five outings.

Spencer Schwellenbach, Atlanta Braves

Season stats: 18 GS, 6–7, 3.73 ERA, 1.10 WHIP

Nearly all first-year players experience growing pains, and Schwellenbach is no different. What makes the 24-year-old stand out is how quickly he seemed to have figured things out in the big leagues.

Through his first two career starts, the right hander was 0–2 with nine runs allowed in 9 2/3 innings. Since then, he’s been one of the league’s best pitchers. In 16 outings since June 12, Schwellenbach has a 3.26 ERA and 3.15 FIP with 104 strikeouts and just 17 walks, looking every bit like yet another Braves development success story. If Atlanta can hold off the New York Mets and get into the playoffs, Schwellenbach will certainly be a big reason why—and he’ll be counted on to carry his strong form into October.

Cade Smith, Cleveland Guardians

Season stats: 71 G, 6–1, 2.00 ERA, 0.92 WHIP

If we’re talking about overlooked players, then there had to be at least one relief pitcher included. And Smith has not only been the best among rookies, but he’s quietly been one of the best bullpen arms in baseball all season.

They say that most good relief pitchers are failed starters, but that’s not true of Smith—at least at the professional level. The 6’5” right hander has worked exclusively as a reliever since signing with Cleveland as an undrafted free agent out of the University of Hawaiʻi at Mānoa in 2020, and has been essentially untouchable this year: he leads all relief pitchers in fWAR (2.6) and FIP (1.46), ranks second in strikeouts (98) and has allowed just one home run across 277 batters faced. Closer Emmanuel Clase rightfully gets most of the acclaim as being baseball’s best closer, but Smith is right there in the conversation of 2024’s most dominant relief pitchers.