The duo both sustained setbacks in Saturday's win over West Coast, with Silvagni subbed out of the encounter early due to a knee injury, while Walsh and forward Jesse Motlop (calf) also sustained setbacks.
On Monday the club confirmed Walsh will require two to three weeks of rehabilitation on the hamstring strain that brought his afternoon to a close, adding to an already injury-hit engine room for Michael Voss.
The Blues have already lost Matt Kennedy (knee) for another month, while captain Patrick Cripps missed the win against the Eagles with a corkie and remains no certainty of lining up for the Blues on Friday night against Collingwood.
Midfielder Adam Cerra is also a test with a hamstring complaint. Motlop is battling with calf tightness and will be a test to play this weekend along with fellow forwards Matt Owies (calf) Corey Durdin (shoulder).
Silvagni has avoided structural damage to his knee and instead has sustained a joint sprain, with the club to gain a bettering understanding of his setback in the coming days.
Carlton will face Collingwood at the MCG on Friday night at 7:50pm local time.