The Red Sox optioned Gamboa to Triple-A Worcester on Wednesday.
After being called up from Worcester on Monday, Gamboa will head back to the minors just two days later with Boston needing to clear a spot on the roster for right-hander Sonny Gray (hamstring), who was activated ahead of his start Wednesday in Detroit. Gamboa made his MLB debut in Tuesday's 10-3 win over the Tigers, striking out two batters over an inning of relief. The 29-year-old left-hander will likely move back into a starting role at Worcester.