HAWTHORN coach Alastair Clarkson says the Hawks continue to fear the worst as they wait for results from scans on Michael Osborne's knee injury.

Clarkson spoke on Melbourne radio on Saturday morning following his side's 66-point win over Melbourne at the MCG on Friday night.

Asked for an update on Osborne's injury, Clarkson said he had yet to receive news, but expected Osborne was set for an extended stint on the sidelines.

"I don't think it's looking too good," Clarkson told SEN, adding that Hawthorn's doctors were almost certain Osborne had suffered some structural damage after hyper-extending his knee in the final quarter of the game.

The 29-year-old, who had only just been subbed into the game, hyper-extended his left knee as he attempted to kick while being tackled by Demon Mitch Clark during the fourth quarter.

He was helped from the field by trainers and went straight down the players' race.

Clarkson appeared upset by the injury when he addressed media following the match.

"It doesn't look great at this point in time, sadly," Clarkson said post-match.

"Hopefully we'll get some better news tomorrow, but it's not looking great.

"We're disappointed for 'Os', because he's an important player to our footy club, and to our side.

"We've just got to deal with it if it's the worst case scenario, but hopefully it won't be too bad."

If Osborne has ruptured his ACL he'll join Alex Woodward as the second Hawk to suffer the injury this season.

Woodward hurt his knee during the NAB Cup.

In better news for Hawthorn, key defender Stephen Gilham made a successful return after almost 12 months out with the same injury.

Gilham had a knee reconstruction after rupturing his ACL in round eight last season.

The 27-year-old had 13 disposals and took five marks in his comeback match.

"He (Gilham) is really important to the structure of our defence," Clarkson said.

"We've been leaking a few goals in the back end of our ground for a little while, particularly early this season.

"We just haven't been able to spoil some of those long balls.

"'Gibbo' (Josh Gibson) has been out for a couple, so it was great to get 'Gilly' back, and 'Gibbo' should be available for us next week.

"So we've just got to make a decision on how many talls we play back there, but it'd be nice to have too many talls in our back end rather than too few."