SYDNEY has confirmed that veteran defender Jarrad McVeigh will miss the next six weeks after being forced into surgery on a broken collarbone.

The bad news has continued with midfielder Dan Hannebery set to be sidelined for three weeks with a strained calf.

Fellow midfielder Kieren Jack is also facing a race against time to be fit for next week's encounter with North Melbourne after suffering a knee injury in a bruising encounter against Geelong on Thursday night.

McVeigh landed heavily on his side while laying a tackle in the final quarter, immediately coming to the bench in pain.

He will subsequently have surgery to repair a broken collarbone on Friday evening, with the club confirming that the 33-year-old will now miss most of the side's lead-up to the finals.

"It is always difficult this far out to put a hard and fast prognosis on it but we will say six weeks," Sydney footy boss Tom Harley said.

"He will have a plate inserted, recover from the surgery and rehab accordingly."

Hannebery will also miss most of the next month after his struggles with a troublesome calf injury continued on Thursday night.

The normally reliable midfielder has had a quiet year and was held to just 12 disposals against the Cats.

"Dan has a strained calf and had a similar one in pre-season," Harley said.

"We are certainly not going to rush him back, we will give him every opportunity to get himself fully fit and really impact the remaining month of the season.

"We will let the injury recover and then put another week on top of that, so he can get some good training and match conditioning under his belt."

Jack injured his knee in the opening term, sitting out the remainder of the match, but remains an outside chance to feature against North Melbourne next week.

"It is a grade one medial, so we will assess him later in the week," Harley said.

"With a medial ligament, the tackiness of the ligament is the key and he has had one a couple of years ago, so we know what we are dealing with there.

"We certainly haven’t ruled him out for this week and given the 10-day break before the North Melbourne game we will give him every opportunity."