Steckenrider was placed on Triple-A Las Vegas' restricted list for an undisclosed reason on March 31, the team's official site reports.
Steckenrider signed a minor-league contract with the Athletics on Saturday that includes an invitation to MLB spring training, Matt Kawahara of the San Francisco Chronicle reports.
Steckenrider cleared waivers Tuesday and was outrighted to Triple-A Tacoma.
Steckenrider was designated for assignment Saturday.
Steckenrider was optioned to Triple-A Tacoma on Thursday.
Steckenrider was reinstated from the restricted list Thursday.
Seattle placed Steckenrider on the restricted list Monday.
Steckenrider allowed two runs on four hits in one-third of an inning to earn the hold in Sunday's win over the Mets.
Steckenrider worked a perfect ninth inning without a walk or a strikeout to record his second save of the season in Friday's 2-1 win over the Mets.
Steckenrider recorded his third hold in a win over the Marlins on Sunday, firing a scoreless eighth inning during which he allowed a hit and recorded a strikeout.