Washington Nationals On July 16, 2015, Alvarado signed with the
Washington Nationals as an
outfielder. He made his professional debut in 2017 with the
Dominican Summer League Nationals, hitting .139/.199/.228 with two
home runs and nine RBI over 45 appearances. In 2018, Alvarado was converted into a
pitcher. He made 10 appearances for the rookie–level
Gulf Coast League Nationals, struggling to a 6.59 ERA with 13 strikeouts over innings pitched. Alvarado began 2019 with the GCL Nationals, posting a 2–2 record and 6.00 ERA with 19 strikeouts across 7 games (2 starts).
Seattle Mariners On July 31, 2019, Alvarado,
Aaron Fletcher, and
Taylor Guilbeau were traded to the
Seattle Mariners in exchange for
Hunter Strickland and
Roenis Elías. Down the stretch, he made 6 appearances split between the rookie–level
Arizona League Mariners and Single–A
West Virginia Power. Alvarado did not play in a game in 2020 due to the cancellation of the minor league season because of the
COVID-19 pandemic. Alvarado spent the entirety of the 2021 campaign with the Single–A
Modesto Nuts. In 31 appearances, he struggled to an 0–2 record and 6.60 ERA with 33 strikeouts across 45 innings pitched.
Detroit Tigers On December 8, 2021, Alvarado was selected by the
Detroit Tigers in the minor league phase of the
Rule 5 draft. He split 2022 between the Single–A
Lakeland Flying Tigers, High–A
West Michigan Whitecaps, and Double–A
Erie SeaWolves, registering an 8–3 record and 2.72 ERA with 63 strikeouts and 10
saves across innings pitched. Alvarado returned to the three affiliates in 2023, accumulating a 2–2 record and 5.18 ERA with 40 strikeouts over 33 innings of work. He elected free agency following the season on November 6, 2023.
Miami Marlins On January 25, 2024, Alvarado signed a minor league contract organization. In 41 appearances split between the Single–A
Jupiter Hammerheads and Triple–A
Jacksonville Jumbo Shrimp, he accumulated a 3–4 record and 2.66 ERA with 74 strikeouts and 11 saves across innings pitched. Alvarado elected free agency following the season on November 4.
Athletics On December 10, 2024, Alvarado signed a major league contract with the
Pittsburgh Pirates. He was
designated for assignment following the signing of
Adam Frazier on January 29, 2025. On January 30, 2025, Alvarado was claimed off waivers by the
Athletics. He was optioned to the Triple-A
Las Vegas Aviators to begin the season, and posted a 3.45 ERA with 22 strikeouts and five saves across 14 appearances. On May 9, Alvarado was promoted to the major leagues for the first time. On August 10, he recorded his first career win, tossing scoreless innings of relief against the
Baltimore Orioles. ==References==