Thomas Cosgrove Biography
Thomas Cosgrove is an American professional baseball pitcher who has played in Major League Baseball (MLB) for the San Diego Padres and Chicago Cubs. Born on June 14, 1996, in Staten Island, New York, Cosgrove was drafted by the San Diego Padres in the 12th round of the 2017 MLB Draft and made his major league debut in April 2023. He spent parts of three seasons with the Padres organization before joining the Cubs in 2025. Cosgrove played college baseball at Manhattan College and excels as a relief pitcher capable of recording multiple outs per appearance.
Early Life and Background
Cosgrove grew up in Staten Island, New York, where he attended Monsignor Farrell High School. His passion for baseball developed during his high school years on Staten Island, a borough with a rich baseball tradition that has produced numerous professional players. After graduating from Monsignor Farrell, Cosgrove continued his academic and athletic career at Manhattan College in Riverdale, New York.
At Manhattan College, Cosgrove played for the Manhattan Jaspers baseball team. His performance with the Jaspers attracted attention from MLB scouts. During the summer of 2016, he played collegiate summer baseball with the Wareham Gatemen and later the Chatham Anglers of the Cape Cod Baseball League, one of the premier summer leagues for college players. His success in the Cape Cod League further enhanced his draft prospects heading into his senior year.
Path to Professional Baseball
Cosgrove entered the 2017 MLB Draft with a solid college track record and impressive summer league performance. The San Diego Padres selected him in the 12th round with the 348th overall pick. Being chosen by an MLB organization represented the culmination of years of development and the beginning of his professional journey.
Upon signing with the Padres, Cosgrove began his professional career in the rookie-level Arizona League and also appeared with the Low-A Tri-City Dust Devils during his first professional season. He logged 44+2⁄3 innings across 13 appearances, recording 41 strikeouts and a 3.22 ERA. This initial professional exposure provided him with foundational experience against newer competition.
Thomas Cosgrove Career
Minor League Development (2017–2022)
Following his debut professional season, Cosgrove continued climbing the Padres minor league system. In 2018 with the Single-A Fort Wayne TinCaps, he emerged as a reliable starting pitcher, making 24 appearances (21 starts) and posting a 3-6 record with a 3.71 ERA and 122 strikeouts across 116+1⁄3 innings. His ability to miss bats and work deep into games became increasingly evident during this period.
The 2019 season saw Cosgrove split time between the AZL Padres and the High-A Lake Elsinore Storm, making nine starts overall. The 2020 season was lost to the COVID-19 pandemic, which cancelled all minor league play. When competition resumed in 2021, Cosgrove returned with the Double-A San Antonio Missions and delivered his most dominant minor league performance, compiling a 2.36 ERA with 32 strikeouts in 26+2⁄3 innings across 22 appearances.
Cosgrove split the 2022 season between San Antonio and Triple-A El Paso Chihuahuas. He set a career high with 48 appearances, going 8-2 with a 3.72 ERA and 82 strikeouts in 55+2⁄3 innings of work. His strong performance earned him a spot on the Padres 40-man roster on November 15, 2022, protecting him from the Rule 5 draft and signaling the organization viewed him as a future big-league contributor.
San Diego Padres MLB Debut (2023–2024)
Cosgrove began the 2023 season with Triple-A El Paso before receiving his first major league promotion on April 26, 2023. He made his MLB debut shortly thereafter, marking the realization of his childhood dream. His rookie campaign proved exceptional as he appeared in 54 games for San Diego, compiling a 1-2 record with a 1.75 ERA and 44 strikeouts while recording one save across 51+1⁄3 innings pitched. His ability to retire batters efficiently made him a trusted option in high-leverage situations.
The 2024 season presented significant challenges for Cosgrove. He appeared in only 18 games with the Padres, struggling to an 0-1 record and an 11.66 ERA with 15 strikeouts over 14+2⁄3 innings. The difficult year led the Padres to option him to Triple-A El Paso to begin the 2025 campaign. In four appearances for the Chihuahuas, he posted a 1-0 record with a 7.36 ERA and 2 strikeouts across 3+2⁄3 innings before being designated for assignment on April 6, 2025.
Chicago Cubs (2025)
On April 10, 2025, the Padres traded Cosgrove to the Chicago Cubs in exchange for cash considerations. The Cubs assigned him to Triple-A Iowa. He received a brief call-up to the major league roster, making two appearances for Chicago. In those appearances, he recorded a 2.25 ERA with three strikeouts over four innings, demonstrating his ability to get outs at the highest level when given the opportunity.
The Cubs designated Cosgrove for assignment on August 31, 2025. He cleared waivers and was sent outright to Triple-A Iowa on September 3, 2025, where he finished the season. Following the campaign, Cosgrove elected free agency on November 6, 2025, ending his tenure with the Cubs organization.
Pitching Style and Strengths
Cosgrove has developed into a capable relief pitcher who succeeds by working quickly and recording outs efficiently. His approach emphasizes generating weak contact and missing bats when needed. His experience working across multiple minor league levels, including Triple-A, has prepared him for various high-pressure situations. Throughout his career, he has demonstrated the versatility to work multiple innings or serve in shorter relief roles depending on game circumstances.
Notable Events and Milestones
Cosgrove reached the major leagues after five seasons of minor league development, making his MLB debut on April 26, 2023, with the San Diego Padres. His 2023 rookie season featured 54 appearances, establishing him as a reliable bullpen piece. He recorded his first career save that season. The trade to the Chicago Cubs in April 2025 represented his second major league organization and provided a fresh opportunity to contribute at the highest level.
Thomas Cosgrove Career Statistics
Cosgrove has compiled MLB statistics across three seasons with the San Diego Padres and Chicago Cubs. His professional career spans eight seasons in the minor leagues where he developed into a serviceable big-league arm.
MLB Career Highlights
Through the 2025 season, Cosgrove has appeared in 74 major league games, logging 57 total innings pitched. He owns a career win-loss record of 1-3 with a 3.86 ERA and 62 strikeouts. His rookie season in 2023 was his most productive, as he posted a 1.75 ERA in 51+1⁄3 innings while appearing in 54 games. His brief 2025 stint with the Cubs produced a 2.25 ERA in four innings of work.
Minor League Career Statistics
Cosgrove’s most productive minor league season came in 2022 with San Antonio and El Paso, when he went 8-2 with a 3.72 ERA and 82 strikeouts in 48 appearances spanning 55+2⁄3 innings. In 2021 with Double-A San Antonio, he posted a 2.36 ERA with 32 strikeouts in 26+2⁄3 innings across 22 games. His 2018 campaign with Fort Wayne saw him total 122 strikeouts in 116+1⁄3 innings as a starting pitcher.
| Competition Level | Games | Record | ERA | Strikeouts |
|---|---|---|---|---|
| MLB (2023–2025) | 74 | 1–3 | 3.86 | 62 |
| Triple-A (2022–2025) | 52 | 9–2 | 3.96 | 84 |
| Double-A (2021–2022) | 70 | 8–5 | 2.84 | 114 |
Thomas Cosgrove Personal Life
Education
Cosgrove attended Monsignor Farrell High School in Staten Island, New York, where he first developed as a baseball player. He continued his education and baseball career at Manhattan College, playing for the Manhattan Jaspers from 2015 to 2017. His college career helped him grow into a professional prospect, culminating in his selection in the 2017 MLB Draft.
Personal Life
Cosgrove maintains his connection to Staten Island, where he was born and raised. He is American by nationality. No information regarding spouse or children has been made publicly available. His professional career has taken him across multiple organizations and minor league affiliates, requiring adaptability and resilience throughout his baseball journey.
2025 Season Performance
The 2025 season represented a transitional year for Cosgrove. He began the year with Triple-A El Paso in the Padres organization before being traded to the Chicago Cubs on April 10. The Cubs assigned him to Triple-A Iowa, where he continued to refine his craft between big-league opportunities. He received a brief call-up to Chicago, appearing in two games and recording a 2.25 ERA before being designated for assignment late in the season.
After clearing waivers, Cosgrove accepted an outright assignment to Triple-A Iowa, where he finished the 2025 campaign. His performance at the Triple-A level demonstrated continued competence as a professional pitcher. Following the season’s conclusion, he elected free agency on November 6, 2025, entering the offseason as an unrestricted free agent with hopes of securing a new major league opportunity for the 2026 season and beyond.