Seattle Mariners Then signed with the
Seattle Mariners as an international
free agent on July 2, 2016, receiving a $77,500 signing bonus. He made his professional debut in 2017, starting 13 games for the
Dominican Summer League Mariners and logging a 2–2 record and 2.64 ERA in innings, the biggest workload in his professional career.
New York Yankees On November 18, 2017, the Mariners traded Then and
JP Sears to the
New York Yankees for
Nick Rumbelow. Then spent the 2018 season with the rookie-level
Gulf Coast Yankees, where he started 11 games and posted an 0–3 record and 2.70 ERA with 42 strikeouts across 50.0 innings pitched.
Seattle Mariners (second stint) On June 15, 2019, the Yankees traded Then back to the
Seattle Mariners organization in exchange for
Edwin Encarnación. He spent the remainder of the season split between the rookie-level
Arizona League Mariners, Low-A
Everett AquaSox, and Single-A
West Virginia Power. In 11 combined appearances (9 starts), Then recorded a 1–5 record and 2.98 ERA with 48 strikeouts in innings of work. Then did not play in a game in 2020 due to the cancellation of the minor league season because of the
COVID-19 pandemic. On November 20, 2020, the Mariners added Then to their
40-man roster to protect him from the
Rule 5 draft. He played the entire 2021 season in Everett, starting 14 games and struggling to a 2–5 record and 6.46 ERA with 59 strikeouts in innings. Then missed the beginning of the 2022 season with an unspecified elbow injury. He was activated in August and made 10 appearances for the Double-A
Arkansas Travelers, recording a 5.40 ERA with 14 strikeouts. Then returned to Arkansas to begin the 2023 season. He made 7 appearances for Arkansas, registering a 5.00 ERA with 11 strikeouts and 3 saves in 9 innings pitched. On May 6, 2023, Then was promoted to the major leagues for the first time following an injury to
Penn Murfee. Then made his major league debut that night, pitching a perfect seventh inning for the Mariners against the
Houston Astros. In 9 appearances for Seattle, he had a 4.91 ERA with 5 strikeouts in 11 innings of work. On August 12, Then was removed from the 40–man roster and sent outright to the
Triple-A Tacoma Rainiers. He elected free agency following the season on November 6.
Chicago White Sox On January 24, 2024, Then signed a minor league contract with the
Chicago White Sox. In 14 appearances split between the Double-A
Birmingham Barons and Triple-A
Charlotte Knights, he struggled to a 10.80 ERA with 8 strikeouts across innings pitched. Then was released by the White Sox on July 8.
Bravos de León On May 20, 2025, Then signed with the
Bravos de León of the
Mexican League. He made one appearance for León, failing to record and out and allowing one run on one hit, one walk, and one hit by pitch. Then was released by the Bravos on May 23. ==References==