Carlton star Walsh out of AFL blockbuster

Lochie O'Brien has been added to Carlton's starting 22, with veteran midfielder Jack Newnes to be the medical sub.

Carlton need to defeat their arch-rivals to be assured of a finals berth for the first time since 2013.

Up to 90,000 people are expected at the MCG for arguably the biggest game between the traditional rivals in more than 30 years.

Collingwood will lock in a top-four spot and a double chance in finals if they beat the Blues for the second time this season, but will fall to sixth on the ladder should Carlton win.