Max Gawn during Melbourne's loss to Brisbane in round two, 2023. Picture: AFL Photos

MELBOURNE captain Max Gawn feared he had suffered a third ACL injury on Friday night that could have threatened the rest of his AFL career.

The Demons ruckman hurt his left knee early in the loss to Brisbane at the Gabba and immediately afterwards, the diagnosis was unclear in the changerooms.

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"The word 'ACL' had been floated around, so for someone who's done two and the people in the rooms couldn't tell me if I had or hadn't done it in terms of how my knee was presenting - the worst-case scenario does go (through) your mind," Gawn said on Monday.

"I'm 31, I'm sort-of getting towards the twilight and to do a third knee would have been pretty devastating for my own career.

"I was quite upset for a bit ... the vulnerability to cry, I had a little tear in the changeroom.

"It was a big moment that got put on me in round two, at a time when you're not expecting that news."

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By the following afternoon, Melbourne were able to confirm that Gawn had sprained his medial collateral ligament and would only be out for about four weeks.

Another ACL rupture would have ended his season.

"I did get some really good news in terms of scans, but how we interpret those scans ... is still to come," Gawn said.

"I'm pretty bullish about a return date."

Gawn was also bullish about fellow ruckman Brodie Grundy, who now is Melbourne's No.1 ruckman until he returns.

Grundy was recruited from Collingwood in the off-season after being injured for most of 2022 and Gawn was rapt with how he stepped up against Lions opponents Oscar McInerney and Darcy Fort.

Darcy Fort and Brodie Grundy in action during Brisbane's win over Melbourne in round two, 2023. Picture: AFL Photos

"We needed him on Friday night, that's for sure ... when I went down in the first five minutes it was always going to be a daunting task," Gawn said.

"He did a tremendous job. Who knows how long I'm out for - I still don't know, I haven't been into the club yet."

Gawn could see the funny side on Monday morning as he fronted a media conference to promote Sunday's Round for Reach charity game against Sydney at the SCG.

He handed over a club cheque for $25,000 to the Reach Foundation, co-founded by late Melbourne great Jim Stynes.

Friday's game was held up for several minutes when the power went out.

"I wanted the game to be over as quickly as possible and it ended up being the longest game in history," Gawn said.