HAWTHORN is holding out hope speedster Jarman Impey has avoided damage to his anterior cruciate ligament, but cannot rule out the possibility. 

Impey was helped off the field early in the second quarter of the Hawks' shock win over Geelong on Sunday after hyperextending his right knee after taking a mark. 

The 24-year-old was in immediate pain and the Hawthorn medicos took out the stretcher to take him off the field, but he left instead with the help of trainers. 

Hawks coach Alastair Clarkson said early indications are Impey will miss the rest of this season with lateral ligament damage, but the club is more anxious about a possible ACL injury which would mean 12 months on the sidelines.   

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"We're not really certain at this point in time. When the knee buckles like that you're always fearing the worst. We certainly think he's got some lateral ligament damage so that will have him out for a period of time, we've just got to hope when they scan him that there's no ACL damage," Clarkson said. 

"We've just got to cross our fingers and hope for the best. He's been a really important player for us in the two years he's been here, and this year he's really found his feet. 

"We hope for the best, but if it's a bad one, he'll have to rehab it and get himself going for the middle of next year hopefully."

Impey is consoled by teammate Paul Puopolo and trainers. Picture: AFL Photos

The former Port Adelaide defender has played every game for the Hawks since crossing to the club at the end of 2017 and has become an important player for Hawthorn.

Impey will get his knee scanned either Sunday night or Monday morning, with Clarkson comparing the uncertainty to that which surrounded Giants midfielder Stephen Coniglio when he had his ACL scare at the MCG last week.

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"They're not really certain if [having torn the lateral ligament] if the ACL is implicated in that as well," he said.

"We're at the mercy of the scan and we'll get that information in the next 24 hours without doubt." - Alastair Clarkson

It was the only blemish on an otherwise brilliant day for the Hawks, who kept alive their finals hopes with a strong 24-point win over the ladder leaders. 

Clarkson praised young forwards Mitch Lewis and Tim O'Brien, who both booted three goals in the win, for their contribution, among a smattering of youthful Hawks who stood up against the Cats. 

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"It gives them belief that they can contribute in the role they play [against] a side that has taken all before it today," he said.

"Geelong are a big opponent, on a big day, and when we play a side like that we need 22 contributors and all those guys will get a bit of belief out of that. 

"We haven't been far away, but we haven't been good enough, either, so beating a side like the Cats gives us a bit of belief that we're not too far away."

The result leaves Hawthorn just one win outside of the top eight with an important clash with Brisbane next week in Tasmania.

But Clarkson said the club wouldn't rush back last year's Brownlow medallist Tom Mitchell from his broken leg even if finals were on the horizon.

"It's probably unlikely with 'Mitch'," he said.

"At the time when he had further surgery to remove the hardware that was in his leg … that was the time where we thought 'We'll just take our time with this'.

"Had everything gone absolutely perfect and that hardware in his leg was going to stay in there, but the advice that we had was to take it out once the bone had healed. That's probably set him back three or four weeks, so it's more unlikely than likely [to see him in 2019], I'd suggest."