West Coast has today confirmed that defender Mitch Brown has ruptured the anterior cruciate ligament in his left knee.

Brown’s knee buckled midway through the first quarter of West Coast’s clash with the Bulldogs on Saturday night and he was taken from the field on a stretcher.

WATCH: Brown injures knee

An MRI has confirmed that the 26-year-old will require a second reconstruction on his left knee, which he first injured in 2008 during a pre-season match against Collingwood.

A decision is yet to be made on whether Brown will opt for the LARS treatment or go down the traditional route.

Brown will join fellow backman Eric Mackenzie on the sidelines, after the 2014 Worsfold medallist suffered a similar injury in the club's first NAB Challenge fixture.

Vice-captain Josh Kennedy delivered the news to the media this afternoon and said that Brown has maintained a positive attitude.

"It’s a confirmed ACL which is disappointing for us and for Mitch," Kennedy said.

"I think the scans came back last night and confirmed it.

"He’s done it before and now he’s going down that same path again.

"It’s sad, it’s football, it’s a part of it.

"Brownie’s been through it before and... on the way back [from Melbourne] he was high-spirited about it all."