The Australia international defender picked up the knock during a meeting with Melbourne City and is now facing a lengthy spell on the sidelines
Adelaide United have confirmed that Tarek Elrich ruptured his anterior cruciate ligament in an A-League clash with Melbourne City.
The Australia international lasted just 25 minutes of that contest before being forced from the field.
The 30-year-old full-back suffered the injury after landing awkwardly on his left leg.
He is now facing up to a lengthy spell on the sidelines, with Adelaide announcing that the opinion of medical professionals will be sought before a decision is made on any surgery.