A PERSISTENT knee injury that has dogged Geelong defender Jared Rivers in the back half of 2015 might force him to make a call on his future as early as next week.

The 30-year-old has played 12 games in 2015 and was a late inclusion for last Saturday night's game against the Hawks.

However after being ruled out of the game against the Saints with a knee injury, AFL.com.au understands Rivers faces an uphill battle to return before season's end.

Rivers showed excellent form in the first half of the season before his knee tendonitis flared once again and he has played just two senior games since round 12.

Since that time emerging youngster Jake Kolodjashnij has assumed the role Rivers performed so well for Geelong in 39 games from midway through 2013 until midway through this season.

Rivers indicated to K-Rock recently he was 95 per cent sure this would be his last season but said at the time he still hoped to play 200 games, a milestone that now appears out of reach.

Rivers joined Geelong as a free agent after 150 games with Melbourne. He won the 2004 NAB Rising Star award and was third in the club's best and fairest in 2011.

A brilliant judge of a mark he often played as an undersized defender against some of the game's best forwards and performed admirably.

Like many defenders of the era he didn't attract much attention from the umpires, earning just one Brownlow vote in his career.

Former North Melbourne and Geelong ruckman Hamish McIntosh announced his retirement last month while a bunch of Cats veterans including Steve Johnson, James Kelly (who will miss the Saints game with an ankle injury), Mathew Stokes (who has been omitted), Jimmy Bartel, Andrew Mackie and Corey Enright all face decisions at season's end as to what 2016 holds.