Brown was subbed off during the first quarter of the Lions' 31-point win over St Kilda on Saturday night with a plantar fascia injury.
The injury leaves Brown's career at the crossroads.
He is out of contract at the end of the season and just as recently as two weeks ago said he was undecided about whether to play on in 2014.
Brown has consistently said he would make his mind up at the end of the season.
Brown has played 245 games, won three premierships, a Coleman Medal and been an All Australian twice and has nothing left to prove.
But after overcoming two horrific facial injuries in 2011 – and surviving an off-season bicycle accident with a car – it would be an anomaly to see injury finish Brown's illustrious career.
Post-match Voss said he did not want to speculate on how much time Brown might miss, and he certainly wouldn't speculate on whether it might have been Brown's final game.
"He's in a boot at the moment, (we'll) wait to assess on Monday about the extent of it," Voss said.
"They're not the world's worst injury, but we'll just have to wait and see how long that's going to leave him out for.
"I haven't speculated all year so I'm not about to now."
Voss said Brown was one of the most resilient and toughest blokes he had ever met and the most disappointing thing to him would not be sharing another win with his emerging teammates.
In Brown's absence, the Lions' forward line continued to function well against their undersized opponents.
Daniel Merrett kicked three goals, and 150-gamer Brent Staker added another three to make it 11 in his past five matches since moving forward.
Voss said regardless of the time Brown spends in the grandstands, his absence would provide an opportunity for a younger player – likely to be either Stefan Martin or Jordan Lisle – against Richmond at the MCG next week.
"Our team has to improve by everyone stepping up. The more [players] that take ownership of this group the more we continue to move forward," he said.
"Whether he's not there for a week, whether he's not there for three weeks, whether it's the season - I can't tell at this stage what it is - I just think it's a great opportunity for us."
Michael Whiting is a reporter for AFL Media. You can follow him on Twitter: @AFL_mikewhiting