Grissom (oblique) began a rehab assignment with Single-A Rancho Cucamonga on Sunday, going 2-for-5 with and RBI and a run scored.
Grissom just went on the 10-day injured list one week ago with a left oblique strain, so it's been a quick turnaround for the 25-year-old. He's eligible for activation Monday, and Grissom could be ready to rejoin the Angels' active roster for their road trip which begins Monday in Arizona.