ELLA Roberts has ruptured her ACL, scans have confirmed.
The star Eagle left the ground during the opening minutes of Sunday's clash against Hawthorn after twisting her knee while changing direction.
West Coast confirmed the nature of the injury on Monday morning, saying the 21-year-old would undergo surgery this week.
“We are all saddened by the injury sustained by Ella,” the Eagles' women's footy boss Michelle Cowan said.
“Our priority is to arrange surgery as soon as possible and ensure she receives the very best care, and we will wrap our arms around her throughout this journey.
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“She is a true professional, and we have every confidence she will approach her recovery with the same diligence and determination, fully supported by our medical team.”