The 27-year-old McCaughan has pitched in five major league games, posting a 7.07 ERA in 14 innings. He made one start in 2021.
McCaughan spent most of last season with Seattle’s Triple-A Tacoma affiliate, where he made 25 starts and went 7-8 with a 5.83 ERA. He threw one complete game and struck out 130 batters over 139 innings.
Seattle waived McCaughan on Wednesday to clear a 40-man roster spot after claiming outfielder Canaan Smith-Njigba, the brother of Seattle Seahawks wide receiver Jaxon Smith-Njigba, off waivers.
To open a spot for McCaughan, the Marlins designated outfielder Peyton Burdick for assignment.