While the exact nature of the injury is unknown, it is believed that Waters will not be able to return to the AFL before the Eagles play their final game in August.
The news caps off a thoroughly miserable night for West Coast, which slumped to its 11th loss of the season on the back of a 135-point drubbing by Geelong. The margin was the second heaviest defeat in Eagles history.
Waters was playing in the WAFL after missing two AFL matches due to a suspension for a high hit on Collingwood's Shane O'Bree.
