PHOENIX -- On a night where nearly nothing went right for the Giants’ big league pitching staff, one of their most prized pitching prospects turned in arguably the best outing of his career to date.
Keyner Martinez tied his career high with 11 strikeouts over six dominant frames for Single-A San Jose in its 2-1 win in 11 innings vs. Rancho Cucamonga on Tuesday night at Excite Ballpark. The Giants' No. 10 prospect scattered a pair of singles and walks and struck out a pair of batters in each of his first five innings of work.
Having begun his pro journey as a multi-inning reliever in 2024 before earning starts last summer, this season has been Martinez’s first as a full-time member of a starting rotation. Taking the ball every Tuesday for San Jose, he’s now thrown at least 70 pitches in 10 consecutive outings.
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His latest start featured the 21-year-old completing six innings for the first time as a pro. He had his entire arsenal working, eliciting 19 swings-and-misses while not allowing a runner to reach second base. Six of his 11 punchouts came via his 60-grade slider, which got incredibly funky swings from right- and left-handed batters alike.
“His slider is a legitimate wipeout pitch,” said senior director of pitching development Kyle Haines back in March of Martinez. “He really didn't develop a changeup until May last year and it came on [as well]."
Martinez is the only prospect ranked among the Giants’ Top 30 to own a pair of 60-grade offerings, with his fastball joining his breaking ball. He got four of his punchouts on the pitch, which once again flirted with triple digits.
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The start was a marked improvement from Martinez’s first foray against Rancho Cucamonga back on April 14 when he allowed four runs over 3 2/3 frames. In many regards, Martinez’s season has been a story of two types of outings: he has allowed two runs or fewer in seven of 12 starts, all of which have gone at least four frames; in the other five, he has been lifted before completing four with at least three runs to his ledger.
Entering spring camp, there was debate about who the Giants’ best pitching prospect would be in 2026 and beyond. Blade Tidwell (No. 9), Carson Whisenhunt (No. 11) and Joe Whitman (No. 23) have all made their case in the upper Minors, as has Jacob Bresnahan (No. 7) with High-A Eugene. But there are those who believe Martinez, a $10,000 signee out of Venezuela in July 2023, is just starting to scratch the surface of his potential.