Walker (foot) will throw a three-inning simulated game Wednesday, Greg Johns of MLB.com reports.
The young right-hander played catch Tuesday and reported no soreness in his foot, which resulted in him getting the green light to progress to a sim game on Wednesday. Walker has been on the disabled list for nearly one month, so it's still unclear whether he'll need a rehab start before returning from the DL. Wednesday's simulated game figures to shed light on the Mariners plan for Walker's rehab moving forward.