GEELONG defender Aaron Black will undergo surgery next week to repair the torn anterior cruciate ligament he suffered in Saturday's win over North Melbourne.

The Cats confirmed their worst fears on Tuesday after Black visited specialists.

Playing in just his third AFL match this season after switching from the forward line to defence, Black hyperextended his knee in a marking contest.

Scans revealed more damage that will see the out of contract 27-year-old miss the remainder of the year.

"This is a disappointing result particularly after finding continuity in his football in recent weeks," Geelong general manager of football Simon Lloyd said.

"Aaron is a popular clubman, respected by his teammates and coaches and an all-round great person to have around our club.

"The club will provide all the support possible to Aaron over the coming weeks and a rehab plan will be put in place once surgery is completed next week."

Black's move to defence came after Harry Taylor (plantar fascia) and Lachie Henderson (knee) missed the early parts of the year.

Taylor is expected to return after the round 14 bye, while Henderson will play his second VFL match on Sunday against Port Melbourne.