Romero, 25, hit .283 with three home runs and nine RBIs in 11 games for Tacoma after being sent down on June 29. He hit .196 with 11 extra-base hits, including three home runs, and 11 RBIs in 51 games for Seattle to start the season.
Luetge, 27, was recalled from Tacoma on July 10 to give the Mariners an extra reliever in their all-bullpen start against the Twins. He pitched one scoreless inning in that day's 4-2 loss to the Twins, but didn't appear in the weekend series against the A's.
Luetge has been with the Mariners on three different stints this season and has a 5.40 ERA in 3 1/3 innings over four games. He's 3-1 with two saves and a 3.40 ERA in 26 outings with Tacoma.
Romero provides a right-handed hitting outfielder for a club that has been shy in that department since designating Cole Gillespie for assignment on July 4. The only full-time outfielders on the club since then have been left-handed hitting Dustin Ackley, James Jones, Endy Chavez and Michael Saunders, who is now on the 15-day disabled list with an oblique injury.
The Mariners also announced that they've transferred the rehab assignment of right-hander pitcher Blake Beavan from Class A Advanced High Desert to Tacoma. Beavan has been out since mid-April with a shoulder injury, but made one two-inning start for High Desert last week.
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.