Ex-Mets' First-Round Draft Pick Makes History in MLB Debut

Former Mets’ No. 10 pick Kumar Rocker tossed just four innings, but made history in his first-career start with the Texas Rangers.

Sep 12, 2024; Seattle, Washington, USA; Texas Rangers starting pitcher Kumar Rocker (80) pitches to the Seattle Mariners during the first inning at T-Mobile Park. Mandatory Credit: Steven Bisig-Imagn Images / Steven Bisig-Imagn Images

Three years after being selected 10th overall by the New York Mets in the 2021 MLB Draft, right-handed pitcher Kumar Rocker made his highly anticipated big league debut on Thursday—but for the Texas Rangers. 

In four innings of work, Rocker surrendered just one run—a solo shot by Justin Turner—while scattering three hits, walking two, and striking out seven over 74 pitches. The Rangers’ No. 2 prospect racked up 17 swings-and-misses against the Seattle Mariners, with 13 coming from his devastating slider.

According to MLB.com’s Sarah Langs, Rocker’s slider tied for the third-most whiffs on a single pitch in a player’s MLB debut since the pitch-tracking era began. His 17 total whiffs also set a new record for a Rangers pitcher in their debut. Rocker’s fastball averaged 96.8 mph and touched 97.6 mph. 

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

Rocker, 24, has faced more than his fair share of adversity to reach this moment. The flame-throwing Vanderbilt star burst onto the national stage in 2019 when he threw the first-ever no-hitter in the Super Regionals of the NCAA baseball tournament, fanning 19 batters in a 3-0 win over Duke. That summer, he was named College World Series Most Outstanding Player, winning both of his starts to lead Vanderbilt to the title. He was also honored as Baseball America’s Freshman of the Year. 

Fast forward two years, and Rocker, along and his Vanderbilt teammate, Jack Leiter, were projected to headline the 2021 MLB Draft. Leiter went No. 2 to Texas, but Rocker unexpectedly slipped to the Mets at No. 10 overall. What seemed like a steal for New York quickly turned into a nightmare for both parties. 

After verbally agreeing to a $6 million signing bonus—$1.4 million above the slot value for the 10th pick—the Mets decided not to make Rocker an offer, citing concerns over his physical. Because Rocker had not participated in a program that would have made his medical information available pre-draft, the Mets were able to receive a compensatory selection in the 2022 MLB Draft.

Rocker quietly underwent shoulder surgery in September 2021, with news of the procedure not surfacing until the following spring. Rather than return to Vanderbilt, Rocker opted to pitch for the Tri-City ValleyCats in the independent Frontier League. He made five starts, posting a 1.35 ERA with a 32/4 K/BB ratio in 20 innings. The impressive showcase vaulted him even higher in the 2022 draft, where he went third overall to the Rangers, reuniting with Leiter in Texas. 

Unfortunately for Rocker, injuries persisted. On May 16, 2023, it was announced that Rocker would undergo Tommy John surgery, ending his season. Despite the setback, the 6-foot-5, 245-pound right-hander worked his way back, reclaiming his signature slider, one of the most unhittable pitches in baseball. Before his promotion, Rocker posted a 1.96 ERA, 0.79 WHIP and 13.5 K/9 over 10 minor league outings in 2024. 

With the season winding down, Rocker is expected to make two more appearances. If he remains healthy, he could solidify a spot in the Rangers’ 2025 rotation alongside Leiter. The two Vanderbilt products inject much-needed youth into an injury-plagued pitching staff that struggled after capturing the World Series title last season.

Texas has two other former Mets lined up for its next two starts—Jacob deGrom, who will be making his season debut on Friday after a lengthy recovery from Tommy John surgery, and Max Scherzer, back from a six-week absence due to a shoulder injury.