[6] He signed on June 21, 2017, and was assigned to the Low–A Lowell Spinners, where he spent the whole season, posting an 0–3 record with a 3.63 ERA in 22+1⁄3 innings pitched.

[11] Houck became only the fourth player in Red Sox history to strike out seven or more batters and not allow any runs in an MLB debut game.

[13] Overall with the 2020 Red Sox, Houck appeared in three games (all starts), compiling a 3–0 record with 0.53 ERA and 21 strikeouts in 17 innings pitched.

[15] Houck began the 2021 season on Boston's active roster; he lost one start and made one relief appearance before being optioned to the team's alternate training site on April 7.

[18] Houck was again recalled by the Red Sox on July 16,[19] earning his first major-league save that evening, pitching the final three innings of a 4–0 win over the Yankees in The Bronx.

[19][21] Overall during the regular season, Houck made 18 appearances (13 starts) for Boston, compiling a 1–5 record with 3.52 ERA; he struck out 87 batters in 69 innings.

He was placed on the restricted list prior to a late April series in Toronto, as he was apparently not vaccinated against COVID-19 (required to enter Canada), causing him to miss a start.

The contest was also the first complete game shutout for the Red Sox since Michael Wacha on June 6, 2022, and the last Maddux for Boston since Clay Buchholz in 2014.