Geelong's Mitch Duncan talks to club doctors on Saturday night. Picture: Ryan Pierse/Getty Images AsiaPac.

Geelong midfielder Mitch Duncan has been ruled out for up to 12 weeks after scans revealed he has a broken foot.

The in-form Cat was subbed out of the game against the Swans on Saturday night in the third quarter after enjoying a dominant first half.

Geelong club doctor Drew Slimmon said that Duncan has broken the fifth metatarsal, a bone on the outside edge of the foot.

“That injury often requires surgery, and that’s what we’re looking at doing for Mitch to give him the best opportunity of getting back as quickly as possible,” Slimmon told the club’s website.