Koehler (shoulder) has progressed to throwing off flat ground from 75 feet, the Associated Press reports.

EDGE Analysis

Koehler kicked off a throwing program at extended spring training last week and is expected to remain in Arizona until he's ready to begin a minor-league rehab assignment. The right-hander was transferred to the 60-day disabled list shortly after Opening Day and won't be eligible for activation until late May at the soonest.