On a disappointing day for Hawthorn, star forward Mitch Lewis suffered a cruel setback during their 51-point defeat to Geelong at GMHBA Stadium on Saturday.

Lewis, who was making his return after a prolonged knee injury, left the field with a bleeding head and apparent knee pain following a collision with Geelong's Jake Kolodjashnij in the fourth quarter.

In his post-match press conference, Hawks coach Sam Mitchell expressed concern but remained hopeful about Lewis's condition.

"It was a fair bit of blood, and he was a bit battered after the game, a bit sore and sorry for himself," Mitchell said.

He noted that while Lewis was cleared of concussion, the extent of his knee injury remains uncertain.

Mitchell had not yet received a detailed medical update on Lewis.

"I haven't spoken too much to the medical guys, I'm not sure what's come out of the game yet. Hopefully he's not too bad; he was probably a bit too courageous in that incident," Mitchell commented.

Updates this morning raise fear of further weeks on the sidelines for the returning star.

Despite the loss, Mitchell maintained perspective on the team's performance and growth against a quality team in hostile territory.

"They are a good side, and we're far from a finished product. We've had a good block of games, but there's still a gap between us and the top teams,โ€ he said.

He acknowledged that while the Hawks matched the Cats in clearances, Geelong's dominance in playmaking set the tone of the game.

Mitchell's focus now shifts to the next match and the health of his key players.

The Hawks will be sweating on the results of Lewis's knee scans as they prepare for their clash against Fremantle.

The hope is that Lewis's setback is minor, allowing him to rejoin his teammates soon and contribute to the Hawks' push towards the finals.