Liddi was available for Wednesday night's game against the host San Diego Padres.
The move was made because Maurer has struggled in the Seattle rotation. He went 2-7 with a 6.93 ERA in 10 starts and has given up 12 runs in his last two outings.
The Mariners will have to make another roster move to fill Maurer's spot in the rotation, which will come up on Sunday in Minnesota.
Liddi, primarily a corner infielder, batted .267 with nine home runs and 37 RBIs in 50 games for Tacoma.