Kai-Wei Teng Bio
Kai-Wei Teng is a Taiwanese professional baseball pitcher currently in Major League Baseball (MLB). After developing through the minor leagues, he reached the majors with the San Francisco Giants in 2024 and has continued his career in the big leagues. Born on December 1, 1998, he represents a growing wave of Taiwanese players making an impact on the highest level of the sport.
Teng first gained attention as an international prospect after signing with the Minnesota Twins in 2017, and he later contributed to a gold-medal run for Chinese Taipei at the 2019 Asian Baseball Championship. His path has included stints at every level of the minor leagues, a brief MLB debut, and a return to the Giants before being traded to the Houston Astros in 2026.
Early Life and Background
Kai-Wei Teng was born on December 1, 1998, in Taiwan. He grew up in a country where baseball has long been one of the most popular sports, surrounded by a strong youth development system and passionate fan base. Taiwanese baseball has produced many major leaguers, and Teng entered the sport through that competitive pipeline.
For high school, Teng attended Shi Yuan Senior High School in Taichung before transferring to Kao-Yuan Vocational High School of Technology & Commerce in Kaohsiung. The move gave him exposure to a different baseball environment on the southern side of the island. After completing his secondary education, he enrolled at National Taiwan Sport University, where he continued to develop as a pitcher while balancing his studies.
Path to Baseball
Teng’s combination of size, arm strength, and poise on the mound quickly made him one of the more intriguing Taiwanese amateur pitchers of his generation. His performances in domestic competition drew the attention of Major League Baseball scouts, and his selection in the 2017 signing period confirmed his standing as a top international prospect.
On October 20, 2017, the Minnesota Twins signed Teng for a $500,000 signing bonus, marking his official entry into professional baseball. That same year, he also represented Chinese Taipei at the 2019 Asian Baseball Championship, where he pitched in the gold medal game against Japan and helped Taiwan secure the title. The championship run added to his reputation as a pitcher capable of performing on big stages.
Kai-Wei Teng Career
Early Career (2018–2019)
Kai-Wei Teng made his professional debut in 2018 with the rookie-level Gulf Coast League Twins. Across 10 appearances, including nine starts, he posted a 3.59 ERA with 47 strikeouts in 42 2/3 innings pitched, signaling a strong first taste of professional baseball. The performance confirmed that his amateur success could translate to the pro game.
He opened the 2019 season with the Cedar Rapids Kernels of the Single-A Midwest League and was named the league’s pitcher of the week for the week ending July 14. In nine games for Cedar Rapids, he logged a 4–0 record and a 1.60 ERA, dominating opposing hitters before a midseason trade changed his organization.
Minnesota Twins to San Francisco Giants Transition (2019)
On July 31, 2019, the Twins traded Teng, along with Jaylin Davis and Prelander Berroa, to the San Francisco Giants in exchange for reliever Sam Dyson. The deal sent Teng to a new organization and a new developmental path on the West Coast. He quickly adjusted, making five starts for the Single-A Augusta GreenJackets and recording a 1.55 ERA with 39 strikeouts in 39 2/3 innings of work.
San Francisco Giants Development (2020–2023)
The 2020 minor league season was canceled because of the COVID-19 pandemic, keeping Teng off the mound for an entire year. He returned in 2021 with the High-A Eugene Emeralds, where a 10-game suspension in June for a foreign substance found in his glove briefly interrupted his progress. In 21 starts for Eugene, he recorded a 4.33 ERA with 142 strikeouts in 95 2/3 innings, showing the strikeout ability that has defined his career.
Teng spent the 2022 season with the Double-A Richmond Flying Squirrels, making 28 starts and registering a 6–12 record and 5.22 ERA with a career-high 169 strikeouts in 136 1/3 innings pitched. The workload and the strikeout totals underlined both his durability and his swing-and-miss stuff. In 2023, he split the year between Richmond and the Triple-A Sacramento River Cats, combining for a 4.75 ERA with the River Cats and a 6–5 record with a 4.22 ERA and 96 strikeouts in 76 innings at Triple-A. On November 14, 2023, the Giants added him to their 40-man roster to protect him from the Rule 5 draft, a clear sign he was closing in on the majors.
Major League Debut and Giants Return (2024–2025)
Kai-Wei Teng was promoted to the major leagues for the first time on March 29, 2024, and made his MLB debut in relief of Daulton Jefferies. He pitched three innings, allowing four hits and three runs. In four appearances during his rookie campaign, he struggled to a 9.82 ERA with seven strikeouts over 11 innings, and the Giants designated him for assignment on November 19 before non-tendering him on November 22, making him a free agent.
On November 29, 2024, Teng re-signed with the Giants organization on a minor league contract. In 25 appearances for Triple-A Sacramento, he posted a 3-2 record and 3.67 ERA with 86 strikeouts and two saves over 54 innings of work. The Giants selected his contract on August 1, 2025, returning him to the active roster, and he made his first major league start that night, pitching 3 1/3 innings in a loss against the New York Mets. He earned his first MLB win on August 8, pitching five innings in relief of opener Matt Gage against the Washington Nationals, finishing the year with a 2-4 record and 6.37 ERA with 39 strikeouts across 29 2/3 innings in eight appearances.
Houston Astros Era (2026–Present)
On January 29, 2026, Teng was traded to the Houston Astros in exchange for Jancel Villarroel, opening a new chapter in his career. He made the Astros’ Opening Day roster and began the 2026 season in the bullpen before shifting to the starting rotation by late April, where he remained into mid-June. A highlight came on June 15, 2026, when Teng and Detroit Tigers infielder Hao-Yu Lee recorded the first head-to-head matchups between Taiwanese baseball players in Major League Baseball, a milestone moment for both players and for Taiwanese baseball.
Driving Style and Strengths
Teng is a power-armed pitcher whose game is built around missing bats, as shown by season strikeout totals such as 169 in 2022 and 142 in 2021. He has shown the ability to work deep into games and to adjust between starting and relieving, including a transition to the Astros’ rotation during the 2026 season. His experience moving from Single-A all the way to the majors has also made him a steady presence on the mound.
Notable Events and Milestones
Among Teng’s most significant moments are his MLB debut on March 29, 2024, his first MLB win on August 8, 2025, and his role in the first Taiwanese-vs-Taiwanese MLB matchup with Hao-Yu Lee in June 2026. He also contributed to Chinese Taipei’s gold medal at the 2019 Asian Baseball Championship and was included on Taiwan’s roster for the 2023 World Baseball Classic.
Kai-Wei Teng Career Wins
Kai-Wei Teng’s career has featured steady progression through the minor leagues and a growing list of accomplishments at the major league level. His first MLB victory came on August 8, 2025, when he pitched five innings in relief against the Washington Nationals. Across various minor league stops, he has racked up multiple wins while consistently logging high strikeout totals.
Minor League and Major League Highlights
At the Single-A level, Teng posted a 4–0 record with a 1.60 ERA in nine games for the Cedar Rapids Kernels in 2019, then a 1.55 ERA across five starts for the Augusta GreenJackets after his midseason trade. In the majors, his first win in 2025 was a milestone, and through his early 2026 work with the Astros, he continued to add to his major league totals.
International Highlights
On the international stage, Teng played for Chinese Taipei in the 2019 Asian Baseball Championship and pitched in the gold medal game against Japan, contributing to Taiwan’s title. He was later included on Taiwan’s roster for the 2023 World Baseball Classic, while he declined to join the team for the 2026 World Baseball Classic.
Kai-Wei Teng Family
Family Background and Racing Lineage
Public information about Kai-Wei Teng’s parents and family background is limited, and detailed family records are not widely available.
Personal Life
Teng keeps his personal life largely private, and no confirmed public details about a spouse or children are available at this time.
2025 Season Performance
Kai-Wei Teng’s 2025 season was defined by a return to the major leagues after a year away from the big league roster. After re-signing with the Giants on a minor league deal in late 2024, he impressed at Triple-A Sacramento with a 3.67 ERA and 86 strikeouts in 54 innings across 25 appearances, forcing the Giants to bring him back to the majors in August.
Once back in the majors, Teng delivered his first career win on August 8 against the Washington Nationals, a notable milestone in a season otherwise spent adapting to the demands of MLB hitters. In eight appearances and seven starts for San Francisco, he finished the year with a 2-4 record and a 6.37 ERA with 39 strikeouts across 29 2/3 innings of work, showing flashes of his strikeout upside while continuing to adjust to the top level of competition.
The momentum from his late-season call-up carried into the offseason, when the Astros acquired him in a January 2026 trade. His 2025 performance served as a springboard, demonstrating that he could compete in the majors and laying the groundwork for his transition to Houston’s rotation.
