Fien, who signed a one-year, $1.1 million contract as a free agent over the offseason, has given up 10 runs on nine hits and four walks in six innings over six appearances with Seattle. He has a career record of 17-17 with a 4.29 ERA in nine Major League seasons with the Tigers, Twins, Dodgers and Mariners.
Fien pitched four games with Tacoma earlier in the season, posting a 2.08 ERA with four hits and one run in 4 1/3 innings.
Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.