CARLTON defender Alex Silvagni is set to miss up to a month after injuring his knee against Greater Western Sydney on Sunday. 

Silvagni, 29, suffered the injury in the first quarter of the Blues' thrilling one-point victory over the Giants and did not take any further part in the match following that incident.

The former Fremantle defender had scans on Monday that revealed the severity of the injury.

The full injury list: round 13

"He just landed on it (his left knee) awkwardly and he's got a bone bruise in that knee joint on the left side," Carlton football manager Andrew McKay told the club's website.

"We're still unsure how long he's going to be out but it's probably going to be 3-4 weeks."

The young Blues defence are already without experienced defender Sam Rowe who suffered a season-ending knee injury against Fremantle in round nine.

However, Liam Jones' return to the side against the Giants and into a new role in defence for the Blues, provides a replacement for Silvagni.