Jansen (pelvis) will pitch for Triple-A Toledo on Tuesday, Evan Woodbery of MLive.com reports.
Jansen landed on the 15-day injured list in late May due to pelvic inflammation. He's progressed enough in his recovery to embark on a rehab assignment and could be reinstated from the IL when eligible June 12. Prior to his injury, Jansen posted a 4.80 ERA, 1.20 WHIP, seven saves in 11 attempts and a 19:9 K:BB across 15 innings.