The OTHER Martinez reliever…
If Arizona is quietly cornering the market in Corbins, they also appear to be making a push for the more specialist category, of relievers called Martinez. We all know about Justin, the flame-throwing bullpen arm, who might end up closing games for the Diamondbacks at some point this year. But in November, the team added Seth, selecting him off waivers from the Houston Astros. The right-handed pitcher had originally been a 17th-round pick by the Oakland Athletics in 2016, but moved to the Astros in the minor-league portion of the 2020 Rule 5 draft. He made his major-league debut for Houston the following year, and since has posted a 3.93 ERA (103 ERA+) over 137.1 innings, with a K:BB of 122:54.
His connection to our state actually goes back considerably further, with Martinez born in Arizona. His parents were both athletes, with mother Kelly being is a former volleyball coach at Buena High School in Sierra Vista, while dad Bobby was a multi-sport star in his days at Bisbee HS, and coached high school ball. After playing Little League in Sierra Vista, Seth went to Sunrise Mountain HS in Peoria, and went 19-4 with a 2.86 ERA there, including a no-hitter against Thunderbird HS during his junior season. He then moved on to ASU, whose recruiting coordinator Ken Knutson called Martinez, “the top arm in the state” and “a really premium strike thrower who has a chance to be a harder thrower as he matures.”
Seth pitched three seasons for the Sun Devils, and in his junior year went 9-4 with a 2.75 ERA and a K:BB of 94:35 across 111.1 innings. That included two complete games, and also a save against Cal State Fullerton, where he worked the 14th inning. He opted to accept the Oakland offer (the same draft saw them pick current D-back A.J. Puk in the first round), rather than return for his senior year. Even at the time, Martinez was seen by some as “undersized” for a starter, and he ended up transitioning from the rotation to become a full-time reliever after the 2017 season in the A’s farm system. This might have made sense, when working both roles in 2017, he had a 4.13 ERA as a starter, but 2.29 out of the bullpen.
He looked particularly impressive in the second half of 2019, after getting promoted to the Double-A Midland RockHounds. He allowed four earned runs over 28.2 innings, for a 1.26 ERA, with 33 strikeouts. Seth wasn’t able to build on that, due to the cancellation of the next minor-league season, but it got him on the radar of the Astros, who plucked him away from the Athletics that December. Since then, his Triple-A numbers have been excellent – a 2.66 ERA and 135 strikeouts in 105 innings. The major-league figures haven’t been quite as good, since an excellent rookie campaign in 2022, where Martinez had a 2.09 ERA, while striking out very close to a batter per inning.
However, I do note that eleven of his appearances last year were for two innings or more, so he could potentially offer Torey Lovullo a spot of length out of the pen. On the other hand, he is far more effective with the platoon edge. In his career, he has held 355 right-handed batters to an average of just .198. But the 233 left-handed batters have feasted on Martinez to the tune of a .307 average, with more walks than strikeouts as well. A long outing would therefore only make sense if Seth got to face a slew of righties. It’s also worth noting that Martinez is out of minor-league options, so he won’t be able to be sent down to the minors without going through waivers again.
That may be of significance, because it’s not the case for most of the anticipated members of the Diamondbacks bullpen this season. One imagines that the other Martinez, Puk, Ryan Thompson and Kevin Ginkel have their roster spots locked up for Opening Day, good health permitting. There is the suggestion the team may also look to add another relief arm, although this probably won’t happen until some salary room is freed-up, most likely with the trade of Jordan Montgomery. Looking at the relievers available on the 40-man roster right now, the most likely candidates for the remaining four spots would include Bryce Jarvis, Joe Mantiply, and a healthy Kyle Nelson. But all of them also have options left.
My instinct is, if the season were to start tomorrow, Seth probably would be on the Opening Day roster. However, it feels like he’s very much at the back of the depth chart, perhaps behind everyone mentioned in the paragraph above, with the lack of minor-league options arguably the biggest thing in favor of him keeping a roster spot. Having arrived on a waiver claim, it’s not as if the team exactly has a lot invested in Martinez (though personally, I always like having Arizona natives playing for the Arizona Diamondbacks!). That said, the team has had some success with cheap pick-ups, such as Thompson, though success is certainly never guaranteed with these.