Seth Martinez Bio
Seth Antonio Martinez, born on August 29, 1994, is an American professional baseball pitcher who is currently a free agent. He has played in Major League Baseball (MLB) for the Houston Astros and the Miami Marlins, working primarily as a reliever. A graduate of Arizona State University, Martinez has built his career through perseverance in the minor leagues before reaching the majors in 2021.
Originally from Sierra Vista, Arizona, Martinez developed into a reliable arm out of the bullpen, capable of handling multiple innings when needed. He has spent parts of five MLB seasons at the highest level and continues to seek his next opportunity after electing free agency in September 2025.
Early Life and Background
Seth Antonio Martinez was born on August 29, 1994, in Sierra Vista, Arizona, and grew up in Peoria, Arizona. He is the son of Bobby and Kelly Martinez, and he has one sister, Taylor. His father, Bobby Martinez, worked as a high school baseball coach, which helped shape Martinez’s early understanding of the game and the discipline required to compete at higher levels.
Martinez attended Sunrise Mountain High School in Peoria, where he played both baseball and golf. Over three varsity seasons, he posted an impressive 19-4 record with a 2.86 earned run average (ERA) and 172 strikeouts across 144 innings. During his junior year, he threw a no-hitter and earned second-team All-State honors, establishing himself as one of the top pitching prospects in the state of Arizona.
Path to Major League Baseball
Following high school, Martinez played three seasons of college baseball for the Arizona State Sun Devils. As a freshman, he worked as both a starter and a reliever, finishing with a 5-0 record and a 4.32 ERA. He also played summer baseball for the Bellingham Bells, gaining valuable experience against wooden-bat competition.
During his sophomore season, Martinez began as Arizona State’s mid-week starter before being elevated to the number one starter in the rotation after seven starts. As a junior in 2016, he went 9-4 with a 2.75 ERA and 94 strikeouts over 111 and one-third innings. That year he was named first-team All-Pac-12 Conference and a Louisville Slugger second-team All-American, with his primary catcher being fellow future major leaguer Brian Serven.
Seth Martinez Career
Early Career in the Minor Leagues (2016–2020)
The Oakland Athletics selected Martinez in the 17th round of the 2016 MLB draft. After signing, he was assigned to the Arizona League Athletics before beginning the 2017 season with the Low-A Vermont Lake Monsters. He was promoted to the Single-A Beloit Snappers after one start and went 5-10 with a 3.49 ERA over 95 and one-third innings that year.
In 2018, Martinez returned to Beloit and converted to a full-time reliever, leading the Snappers with 15 saves. He began 2019 with the High-A Stockton Ports of the California League and was promoted to the Double-A Midland RockHounds, where he increased his strikeouts and lowered his ERA against stiffer competition. Martinez did not play in a game in 2020 due to the cancellation of the minor league season caused by the COVID-19 pandemic.
Houston Astros Era (2021–2024)
On December 10, 2020, the Houston Astros selected Martinez in the minor league phase of the Rule 5 draft and assigned him to the Triple-A Sugar Land Skeeters for 2021. He made his MLB debut on September 20, 2021, pitching a scoreless ninth inning. After another scoreless outing, his rookie season ended with five runs allowed in the final inning of a blowout loss to Oakland.
During the 2022 season, Martinez joined the Astros near the end of April and worked as a long reliever. He threw 17 and two-thirds scoreless innings to start the year before allowing a game-winning 10th-inning home run to Aaron Judge. He posted a 2.48 ERA over 32 and two-thirds innings through August 13, was briefly demoted to Triple-A, and was recalled on August 25. On September 15, 2022, Martinez earned his first major league win with a scoreless inning against the Athletics, finishing his rookie year 1-1 with a 2.09 ERA in 29 games and 38 and two-thirds innings.
In 2023, Martinez again split time between the majors and Triple-A. He recorded his first major league save on June 25, pitching in the 11th inning of a win over the Los Angeles Dodgers. He finished 2-3 with a 5.23 ERA in 43 innings for the Astros, while posting a stronger 2.25 ERA in 19 games with the Skeeters. During the 2024 season, Martinez appeared in a career-high 44 games with Houston, going 3-2 with one save and a 3.59 ERA over 52 and two-thirds innings, also a career high. He finished 14 games, recorded 36 strikeouts, and posted a 1.272 walks plus hits per inning pitched (WHIP).
Miami Marlins Era (2025)
Martinez’s time with the Miami Marlins was eventful. After being claimed off waivers by the Arizona Diamondbacks on November 4, 2024, he was designated for assignment on February 17, 2025. Three days later, he was claimed by the Miami Marlins, designated for assignment again on February 27, claimed by the Seattle Mariners on March 2, and reclaimed by Miami on March 15. He was designated for assignment once more on March 26 and cleared waivers, being sent outright to the Triple-A Jacksonville Jumbo Shrimp.
With Jacksonville in 2025, Martinez went 3-2 with a 3.71 ERA, 54 strikeouts, and eight saves over 43 and two-thirds innings in 41 appearances. On August 27, the Marlins selected his contract and added him to their active roster. In six appearances for Miami, he posted a 5.40 ERA with four strikeouts across six and two-thirds innings. He was designated for assignment on September 11 and elected free agency on September 13 after clearing waivers.
Driving Style and Strengths
Martinez is recognized for his versatility as a reliever, with the ability to pitch multiple innings when needed. His career highlights include stretches of long relief, a full-time closer role in the minors, and performances against high-level hitters such as Aaron Judge and the Los Angeles Dodgers.
Notable Events and Milestones
Among Martinez’s signature moments are his MLB debut on September 20, 2021, his first major league win on September 15, 2022, and his first major league save on June 25, 2023. He is also a member of the Houston Astros organization that earned a World Series ring ceremony, despite not pitching in the postseason during his rookie year.
Seth Martinez Career Wins
Throughout his professional career, Seth Antonio Martinez has compiled a verified major league record of 6-6 with a 4.00 ERA and 126 strikeouts through the 2025 season. His major league wins came primarily during his time with the Houston Astros.
MLB Highlights
Martinez earned his first major league win on September 15, 2022, after tossing a scoreless inning against the Oakland Athletics. His career-high workload came in 2024 with the Astros, when he went 3-2 with one save and a 3.59 ERA across 44 games and 52 and two-thirds innings.
Seth Martinez Family
Family Background and Baseball Lineage
Seth Antonio Martinez is the son of Bobby and Kelly Martinez. His father, Bobby Martinez, was a high school baseball coach, providing Seth with an early foundation in the sport. He also has one sister, Taylor.
Personal Life
Martinez grew up in Peoria, Arizona, and attended Sunrise Mountain High School before continuing his baseball career at Arizona State University. He has kept most details of his personal and family life private.
2025 Season Performance
The 2025 season was a turbulent year for Seth Antonio Martinez at the major league level. He was claimed off waivers multiple times before settling with the Miami Marlins organization, where he spent the bulk of the season with the Triple-A Jacksonville Jumbo Shrimp. At Jacksonville, he posted a 3-2 record with a 3.71 ERA, 54 strikeouts, and eight saves over 43 and two-thirds innings across 41 appearances, establishing himself as a dependable late-inning arm.
Martinez was promoted to Miami’s active roster on August 27 and appeared in six games, recording a 5.40 ERA with four strikeouts across six and two-thirds innings. He was designated for assignment on September 11 and elected free agency on September 13 after clearing waivers, closing the book on his Marlins tenure.
