Hoerner (hamstring) will begin a rehab assignment Sunday with Triple-A Iowa, Meghan Montemurro of the Chicago Tribune reports.
Hoerner's left hamstring strain has now kept him out for a full month. The length of his absence means he may need more than just a game or two before he returns to the big-league roster, but he should be back fairly soon. The Cubs will be excited for his return, as he hit a strong .338/.405/.432 in 21 games prior to the injury.