Essendon defender Patrick Ambrose could miss as many as 10 weeks after scans confirmed he injured his posterior cruciate ligament in a practise match on Friday.
The hard-nosed 29-year-old picked up the injury in the first quarter of the scratch match as he attempted a spoil over a Melbourne opponent.
Essendon football boss Dan Richardson said Ambrose would meet with a specialist to map out the lengthy recovery process.
"Scans have confirmed the views of our medical team that Paddy suffered an injury to his PCL during a marking contest in Friday’s practice match,” he told the club’s website on Saturday.
“The club will consult with a specialist in the coming days.”
The injury is another bitter blow to the Bombers, who have had to battle with a spate of injuries throughout pre-season.
With Cale Hooker (hip) and Michael Hurley (shoulder) still recovering from injury and Conor McKenna on indefinite leave in Ireland, it could be up to Aaron Francis to lead Essendon’s depleted backline against Fremantle in round one.
The Bombers open their Marsh Community Series against West Coast in Perth on Thursday night (AEDT).