HAWTHORN coach Alastair Clarkson has revealed that Stephen Gilham's season is likely to be over after the defender sustained a serious knee injury in the win over St Kilda at the MCG on Sunday.

The Hawthorn coach admitted to "mixed emotions" after the gutsy 30-point victory over the Saints, with the Hawks losing Gilham and David Hale in the first half with suspected serious knee injuries.

The Hawks, who this season have already lost promising defender Ben Stratton to a knee injury, saw Gilham leave the field in the opening minutes after the 26-year old twisted his right knee trying to change direction away from opponent Ben McEvoy.

In 2009, Gilham missed 10 matches after hyper-extending his left knee in a NAB Cup match and Clarkson wasn't holding out hope of a miracle, with the defender set to have scans on Monday.

"It's just a hard one with someone like 'Gilly' who has been such a stalwart for our defence for the last five to six years," Clarkson said.

"To lose him for 12 months on the back of Stratton being out for 12 months as well, it is going to hurt our back end."

But the outlook could be brighter for Hale, with the coach confident the ruckman's injury wasn't as bad at first thought when he was stretched off after landing awkwardly in a spoiling attempt.

The injuries overshadowed the Hawks' brilliant win after the team found themselves 33 points down early in the second quarter before mounting a sensational comeback despite being limited to two players on the bench.

After failing to register a goal in the first term, the Hawks had all the momentum in the second quarter, kicking 5.7 to the Saints solitary behind as Clarkson's men smashed the Saints in the inside 50 count 20-2 for the term.

"It was such an unbelievable effort by our guys to come back from five goals down and losing two important big players … the resilience of the group was just superb today."

The performance of Jarryd Roughead won special praise from Clarkson, after the Hawk forward was forced to ruck for the majority of the match after the injury to Hale.

"It was such a lion-hearted effort today to not only get in there and compete but we won the clearances convincingly," he said.

Clarkson, who during the week said the clash against the improving Saints would give his players a true indication of where they stood in the competition, hoped the side could build on this win and push towards a top-four berth.

"Not sure if they will be able to draw from it in weeks to come, but hopefully they can because it was a real great victory for our club," he said.

"[It was] a very important win for our football club today, especially given the circumstances, and hopefully we can build our season from this point."

Hawthorn travels north to take on the Sydney Swans next Sunday afternoon, hoping to record its first win in Sydney since 2003.