It will rule the 27-year-old out of the Eagles' Marsh Community Series clash against Essendon on February 27.
Darling will also be unavailable for selection in the State of Origin Bushfire Relief match (February 28), with doubt around his place in the Eagles' second pre-season hitout with Fremantle (March 7).
"It was friendly fire in training and unfortunately he has a small fracture of the cheekbone," Eagles head of football Craig Vozzo told westcoasteagles.com.au.
