Motter was recalled from Triple-A Tacoma on Sunday, Ryan Divish of The Seattle Times reports.
He'll take the roster spot of Danny Espinosa, who was placed on release waivers in a corresponding move. Motter spent some time with the Mariners earlier in the season, slashing .204/.272/.355 with seven homers and nine stolen bases in 70 games before being sent back to the minors. Since his demotion, the 27-year-old hit .350 with seven homers and six stolen bases in 25 games with Tacoma. He'll return to his role as a utility player for the big club.