Harry McKay (concussion) and Jack Martin (suspended) will both miss Friday night's sold-out clash at the MCG, leaving Voss with a headache at the selection table.
The versatile Silvagni has been sidelined by a knee injury for almost two months but passed a fitness test this week and looms as a possible inclusion.
"He's certainly available to play," Voss told reporters on Thursday.
"The question that we have to ask is, is he ready?
"Coming in without having played a game first, we have to weigh that up."
Jesse Motlop was the substitute in Carlton's elimination final win over Sydney and shapes as a likely replacement for Martin in the 22.
Voss said it will be important for the Blues' forwards to compete in the air against Melbourne defenders Jake Lever and Steven May.
He could recall big-bodied midfielder-forward Matthew Kennedy or even move Mitch McGovern from defence to attack.
"We'll weigh up what roles we need to be played but clearly having an aerial presence is going to be pretty important," Voss said.
"There's a couple of players down there that go well in the intercept game and they defend as well as any team in the competition.
"It will be a tightly fought match and we'll have to take those opportunities when we can.
"Our boys will have to be able to compete in the air to try to get the ball on the ground."
Melbourne are hoping to get their dysfunctional attack firing against Carlton but will be without young forward Jacob van Rooyen through suspension.
The Demons will have to decide whether to play Ben Brown, after the experienced tall only recently returned to full training after a knee injury.
A recall for ruckman Brodie Grundy could also be on the cards, especially with Max Gawn reportedly nursing a broken toe, while former Western Bulldogs tall Josh Schache is another tall option.
The Demons could also look at smaller types like Charlie Spargo or Taj Woewodin.
James Jordon appears a likely replacement for midfielder Angus Brayshaw, who is sidelined for at least one more game after being knocked out by Brayden Maynard's attempted smother.
Port Adelaide face an agonising call on whether to gamble on spearhead Charlie Dixon's fitness for their do-or-die semi-final against GWS.
Power forward Dixon hasn't played since the round-20 loss to Adelaide on July 29 due to a foot injury.
He has booted 22 goals in 13 games and when fit is clearly the focal point of Port's attack.
Dixon had limited involvement in training on Monday, when teammate Connor Rozee described him as a "big chance" to face the Giants.
The Power will have their main training session on Thursday night when those pushing to prove their fitness will get one last chance at staking their claim.
That includes fellow forward Todd Marshall, who battled through a hip injury in the qualifying-final loss to the Brisbane Lions.
Port are also sweating on the fitness of defenders Dylan Williams (hamstring) and Trent McKenzie (ankle).
GWS need to squeeze star midfielder Stephen Coniglio back into a winning team at Adelaide Oval on Saturday.
Coniglio was a late withdrawal from the Giants' elimination-final win over St Kilda with an eye injury but was always going to be ready for the semi-final.
Late inclusion Xavier O'Halloran impressed against the Saints but looms as the likely unlucky man to make way.
"When you have that kind of pressure for selection ... that's a sign of a really good team," gun midfielder Josh Kelly said.
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