Clark - the man whose accidental elbow resulted in Brown’s season-ending facial fractures - kicked three goals against Geelong last week, while Cornelius will play just his third match of the season.
The pair will combine with rookie Pat Karnezis in a revamped Lions forward line against North Melbourne at Etihad Stadium on Saturday.
But Voss said there was no way a single player could cover the loss of Brown.
"If anyone thinks that, then we're in the wrong head space," he said.
"No-one has to do any more than what their job entails. When we try to do more, that's when we become desperate and our system falls apart.
"We know what the basics are and we have to execute those, and as far as our roles go we're not asking anybody to step above.
"If they can bring what they're capable of, then we'll be more than competitive against this team."
Despite going winless for the six matches Brown missed earlier this season, Voss said he felt that stretch helped the team mature.
Cornelius gets another chance after an extended run in the reserves and a five-goal haul last weekend.
The 192cm forward has shown terrific hands in his eight senior matches, but Voss said he was most pleased with the Tasmanian’s improvement in the defensive side of his game.
"It’s a good opportunity for Aaron to come into the team and show us what he’s got and he’s certainly worked on a lot of aspects of his game, attack and defence," Voss said.
"It’s been pleasing to see that he’s gone back and really worked away at that and persisted.
"Hopefully he can step in and do a role like Browny, take his marks, get involved in defence and if he can, kick a couple of goals for us, that’ll be what he’s marked on."
Voss also had his say on the debate over Brown's manic attack on the ball, and said he was surprised at some of the commentary over the past week.
"There's no clouded view where we stand. I've been a bit disillusioned … but that's what they're there to do, to commentate and give their views. He's certainly got the support from us regardless of what's been said," Voss said.
"For us, the acts he does on the field, 99 out of 100 are fantastic. He has one now they're talking about so you can focus on the one or the 99. For me it's the 99, but as far as I'm concerned it's over. "
