Richards had a platelet-rich plasma injection on Friday, the Angels announced. Richards also was examined by Dr. Steve Yoon, who saw continued healing in the pitcher's partially torn elbow ligament.
Richards is hoping to avoid Tommy John surgery with rest, stem-cell therapy and PRP injections. He completed three instructional league outings this month with no setbacks.
Richards will rest his arm for the next 8 to 10 weeks before starting his regular offseason program in January.
After starting for the Angels on opening day, Richards made just six appearances before he was shut down in May.