Originally signed by San Diego and debuting as a 20-year-old fireballer in 2019, Andrés Muñoz’s trajectory faced an immediate obstacle when he needed Tommy John surgery. As a result, the Padres included him as part of a major seven-player trade to Seattle in August 2020. The Mariners' training staff managed his rehab meticulously, transforming him from a raw thrower with triple-digit velocity into one of the most effective and well-rounded closers in professional baseball.

Muñoz’s rise to the top tier of modern relievers is fueled by a remarkable two-pitch arsenal that leaves major-league hitters completely stymied. His powerful, high-90s four-seam fastball, which can hit triple digits, combines with what is arguably the sport’s most devastating breaking ball—a sweeping slider that regularly keeps opponents’ batting averages below .130. After demonstrating his incredible swing-and-miss ability as a high-pressure setup man during Seattle's exciting 2022 postseason run, he smoothly stepped into the closer role. In 2024, he earned his first American League All-Star nod by notching 22 saves and maintaining a stellar 2.12 ERA.

The 2025 campaign was a historic exhibition of absolute, high-leverage dominance. Stepping onto the mound with his trademark calm demeanor, Muñoz served as an ironclad firewall at the back of the bullpen, capturing the AL Reliever of the Month honors for March/April after rattling off 15 consecutive scoreless appearances to start the summer. He paced the Mariners' relief corps with a brilliant 3–3 record and a dazzling, career-best 1.73 ERA across 62.1 frames of work.

True to form, he was completely untouchable. Muñoz shattered a historic franchise record by putting together 12 consecutive hitless appearances from July 5 to August 14. He struck out 83 batters while holding opposing lineups to a comical .167 batting average, converting a career-high 38 saves—making him the first Mariner to eclipse the 30-save threshold since Edwin Díaz's legendary 2018 run. His suffocating era dominance earned him a second consecutive All-Star nod, a spot on the All-MLB Second Team, and critical clean sheets during Seattle's October postseason run.

Entering the highly anticipated 2026 campaign at just 27 years old, Muñoz firmly establishes himself as the premier anchor of a loaded Seattle bullpen, widely projected as one of the most lethal late-inning lock-down units in all of baseball.