Kumar Rocker debut: Rangers prospect strikes out 7 in first MLB start

Texas Rangers ballyhooed right-hander Kumar Rocker made his major-league debut on Thursday night against the Seattle Mariners and turned in a strong and at times dominant outing.

Rocker's line for the night:

Manager Bruce Bochy before the game indicated that Rocker would be limited to five innings or around 75 pitches. Since Rocker was 74 pitches after four, Bochy opted to go to the bullpen with the game tied 1-1 ( TEX-SEA GameTracker ).

Rocker permitted singles through the infield to the first two batters he faced, but he rebounded to register a scoreless opening frame. His first career strikeout was of the called variety with a full-count fastball that froze Cal Raleigh.

Speaking of the fastball, it averaged 96.8 mph and maxed out at 97.6 mph – a bit shy of his best radar readings but still sizzling. As is his tendency, he leaned heavily on his wipeout slider, and Seattle hitters were baffled by it. Rocker threw 33 of them on the night, and the Mariners registered 13 whiffs on 21 swings at the slider. Here's a taste:

Rocker's lone blemish came on a fourth-inning homer by Justin Turner, who punished a fastball that leaked over the plate. Even that mistake, though, comes with a qualifier, as either of the two pitches before the homer could've been called strike three.

Rocker, 24, worked his way to the majors in his comeback season from Tommy John surgery. After getting back up to speed during a rookie-ball stint, Rocker turned in seven dominant starts at the Double-A and Triple-A levels. In his five starts for Double-A Frisco, Rocker pitched to a 0.46 ERA with 29 strikeouts and three walks in 19 2/3 innings. He then made a pair of starts for Triple-A Round Rock, and over that brief span Rocker boasted a 1.80 ERA with 18 strikeouts and only one walk in 10 innings.

Rocker's ascent to the highest level of baseball makes for a compelling story. A frontline ace coming out of Vanderbilt, the New York Mets drafted him with the No. 10 overall pick in 2021 but the Mets attempted to lower the informally agreed-upon signing bonus because of concerns over Rocker's medicals. Rocker didn't blink, however, and the two sides failed to reach an agreement. Rocker then undertook a dominating turn in indy-league ball before re-entering the draft in 2022.

The Rangers then pulled off a stunner by selecting Rocker third overall in 2022. Despite the Tommy John procedure Rocker was forced to undergo last year, the Rangers' faith in Rocker looks poised to be rewarded. That's still the case after Rocker's impressive MLB debut on Thursday night in Seattle.