Rondon made three relief appearances for the Tigers earlier this season, allowing three runs on five hits over 2⅓ innings. The right-handed pitcher has found much more success at the Triple-A level, as he owns a 1.52 ERA with 14 saves in 30 appearances for the Toledo Mud Hens.
The Tigers had originally hoped that Rondon would win the closer's role out of Spring Training, but the reliever struggled, so the team sent him down for more seasoning and consistent work in the minors.
Rondon will find consistent work with the Tigers bullpen now, as the Detroit bullpen enters Friday with a 4.07 ERA, the third worst mark in the American League. Joaquin Benoit has settled into the closer's role, but the team could use some help in middle relief, as Phil Coke and Darin Downs have both struggled in 2013.
To make room for Rondon on the active roster, Detroit optioned rookie right-handed pitcher Evan Reed to Triple-A Toledo.