GEELONG ruckman Dawson Simpson won't play again this season after scans on his injured knee revealed he will need to undergo surgery.

The 24-year-old strained the medial ligament and dislocated the kneecap in his left knee during the Cats' 101-point win over St Kilda on Saturday night.

Simpson had scans on Monday which, according to Geelong coach Chris Scott, showed "significant damage" to his medical ligament and "slight damage" to his posterior cruciate ligament.

"There's a little bit of bone bruising as well," Scott added, "so the initial prognosis is six to eight weeks."

There are only five matches remaining in the home and away season, so Simpson would have to enjoy a perfect recovery, then be rushed back into the team during the finals, if he was to play again this year.

Such a scenario is highly unlikely.

"It is disappointing for everyone," Scott said. "Dawson was shattered after the game, because he's had some setbacks. He's had two bouts of back surgery in the previous two seasons.

"To be honest, early in the season he was a fair way away from AFL selection. So to get to the stage where he not only forced his way in, but was performing at a very high level, makes it all the more disappointing."

The upside for Simpson is that his good form in recent weeks appears to have secured him a spot on Geelong's list for next season.

"I'd just like to reinforce to Dawson in particular that our club, especially in recent times, has a very good record of looking after those players who do the right thing and live the right values, and have some back luck.

"So we'll certainly stand by Dawson."

Geelong's luckless half-forward Daniel Menzel is also preparing to go under the knife this week.

Menzel suffered his fourth serious knee injury when he snapped the LARS graft in his left knee while playing for the Cats' VFL team against Box Hill in late April.

The 21-year-old had surgery to stabilise his left knee joint in early May.

After a period of rehab, he then headed overseas for a holiday, and it is only now that he will have a new ligament inserted into the knee.

"The first bout of surgery went well," Scott explained. "He's been through the recovery process.

"He's got some obstacles in front of him, so the mental break was really important.

"The biggest part about being overseas was that no one recognised him and he didn't get asked about his knee for a few months, which was a good thing."

Despite Menzel's travails, he and the club are adamant that he will play again.

"I think the really pleasing thing for us, for Dan and our supporters, is that in conversations with the surgeon, he doesn't see any reason why this shouldn't just be treated as a normal ACL reconstruction with a normal recovery period," Scott said.

"Then he can come back and be somewhere near his best.

"I know that might sound optimistic, given Dan's history, but we can only go by the best medical advice, and that is that he's every chance to come back next year and be the Dan Menzel he was.

"He's a remarkably resilient young man. He's very confident in his ability and he's going to need that, because he's got some obstacles to get over.

"He's going to have to confront those mental demons at some stage, but of all the young people I've met in footy, I would have the most confidence in 'Menz' to come back."

Adam McNicol covers Geelong news for AFL.com.au. Follow him on Twitter at @AFL_AdamMcNicol