Martinez (foot) is scheduled to take batting practice Wednesday and is expected to begin running on the field Friday, Evan Woodbery of MLive.com reports.
Martinez still looks to be a week or more away from being activated from the disabled list, but the on-field running marks an important step in the recovery process for the outfielder. Since suffering the mid-foot sprain in a March 18 Grapefruit League game, Martinez had been limited to running on a treadmill, so once he's able to show his mobility won't be an issue while covering the field, the Tigers might be able to flesh out a more defined return date. Because he's missed more than a month with the injury, Martinez will eventually require bulk at-bats during simulated games at extended spring training before his activation.