HAWTHORN's Mitch Lewis is expected to miss the start of the season after hurting his knee at training on Monday.

The 24-year-old suffered the injury in an innocuous incident during match simulation at La Trobe University, but completed the session before reporting pain the following day.

Subsequent scans on Tuesday afternoon revealed a sprain of his anterior cruciate ligament.

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The Hawks don't expect the spearhead to require surgery at this stage and will get a clearer timeline around his return in the coming weeks.

But after Lewis emerged as one of the best young key forwards in the AFL last year, it is a big blow for Hawthorn heading into the season.

"He will certainly spend some time on the sidelines though and, at this stage, we expect him to miss Round 1," said team doctor Liam West.

Lewis kicked 37 goals from 15 games in a breakout 2022, but missed the final three rounds of last year due to a jarred knee - the same knee he hurt again this week.

The Victorian returned to full fitness by the start of pre-season and had completed most of the program until this recent setback.

Lewis turned his back on lucrative offers from rival clubs to sign a four-year deal last year to remain at Hawthorn and is considered one of the emerging leaders at the club.

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With All Australian Jack Gunston departing for Brisbane during the trade period and Lewis' return date unclear at this stage, Hawthorn coach Sam Mitchell will need to find some other key options in attack to start 2023.

It could mean the Hawks use two ruckmen in the 22, with recruit Lloyd Meek currently battling Ned Reeves and Max Lynch for a spot in the senior side.

Hawthorn has almost a full list on the track at the moment with only Josh Ward (hip), Conor Nash (knee) and Josh Morris (shoulder) not involved in full training before Lewis joined that group.

The Hawks are set to face Geelong in an organised scratch match late next month, ahead of the league organised practice game at the start of March.