HAWTHORN has suffered a massive blow to its finals chances with in-form ruckman Ben McEvoy ruled out for up to six weeks.

McEvoy had surgery to repair a fractured cheekbone after a nasty clash with Bulldog Josh Dunkley during last week's big win.

McEvoy’s extended absence gives coach Alastair Clarkson plenty to think about ahead of the club’s most critical stretch of games for the season.

In that time the Hawks, 9-6 and eighth on the ladder, meet Brisbane, Carlton, Fremantle, Essendon, Geelong and St Kilda.

MATCH PREVIEW Hawthorn v Brisbane

On paper, the next three weeks shape as the softest part of the schedule for the entire season, although the Hawks won’t be looking any further ahead than the Lions on Saturday afternoon, given the 56-point belting they suffered from them at the Gabba earlier this year.

There will be a level of comfort that the game is at the University of Tasmania Stadium, where the Hawks have lost just twice and drawn once in their past 27 games, but given what happened in round nine, they will have to tread warily. But if they win these next three games, then they will have all but ensured a return to the finals after their gap year in 2017.

One reason for the Hawks’ improved form since that loss to the Lions has been the return of ruckman Jon Ceglar. He played his first game in 21 months the following weekend, when the Hawks lost to West Coast, but he and McEvoy form a terrific partnership because they are both more than capable in the ruck and offer plenty around the ground with their contested marking and their mobility.

Not too many teams are comfortable with the idea of playing two genuine ruckmen, but it has worked for the Hawks and what Clarkson needs to decide for the next six weeks is whether he will continue down that path.

Will he be guided by structure or available personnel?

One slight complication is that back-up ruckman Marc Pittonet left the ground in the final quarter of the Box Hill game last Saturday with an ankle injury and did not return.

The 22-year old, who has played three games at AFL level but none since round 23, 2016, has filled out nicely and is averaging 34.9 hit-outs a game in the VFL and is third for hit-outs to advantage. He will need a fitness test later this week, but the club said on Tuesday that he is expected to play, whether at VFL or AFL level.

If it’s the latter, then he’s not as mobile as McEvoy, but he’ll provide enough of a contest to allow Ceglar to play close to goal for considerable periods and stretch the Lions backline, which will still be missing key defender Harris Andrews, who starred against Hawthorn last time around.

If it’s about personnel, then it will likely lead to another recall for Tim O’Brien, who has been in and out of the side in recent weeks. He can play as a tall in the forward line and provide some ruck relief for Ceglar.

Another option could be Mitch Lewis, the promising second-year forward who played two games earlier this year for Hawthorn but is averaging 2.5 goals a game in the VFL.

Midfielder Daniel Howe, who did a superb shutdown job on Bulldogs star Marcus Bontempelli on Saturday night, wasn't listed on the injury report despite sitting out the final term with knee soreness, so it is assumed he will be available for a role on one of the dangerous Lions midfielders, either Dayne Zorko or Dayne Beams.

Will Langford, who missed last week because of a finger injury, trained on Tuesday and will be available for selection.

According to the Hawks, Shaun Burgoyne is midway through his recovery from his second hamstring strain and will likely be available for the round 19 trip to Fremantle.

And there is finally some progress with four-time premiership defender Grant Birchall, who following the retirement of Cyril Rioli is now one of just two remaining Hawks from the flag-winning 2008 team.

He hasn't played in more than 12 months because of recurring knee injuries, but his running program is proceeding to plan and he will resume ball work next week. He would be a huge addition to the side for the challenging few weeks towards the end of the home and away season, in which the Hawks hope to book themselves not just a finals berth, but perhaps a home final as well.