Lance Franklin's stop-start AFL season has been halted by a knee injury that will further test Sydney's depth and finals ambitions.
Franklin, having only recently returned to full fitness after battling a series of soft-tissue injuries that restricted him to one AFL game in 21 months, will spend up to a month on the sidelines because of bone bruising.
The superstar suffered his latest setback during the third quarter of the Swans' first loss of the season.
The four-time Coleman medallist played on after his clash of legs with GWS defender Connor Idun at the SCG, but felt sore on Sunday and follow-up scans delivered some bad news.
Sydney coach John Longmire has also confirmed that in-form ruckman Tom Hickey will be out of action for six to eight weeks because of his knee injury, also suffered in the derby defeat.
The Swans have proven they can play well without talismanic forward Franklin, most notably and recently when they upset reigning premiers Richmond at the MCG.
Equally, Longmire knows coming weeks will test his third-placed side's stocks.
Dane Rampe (broken finger) and Isaac Heeney (broken hand), who were both enforced omissions for the derby, and Hickey had also been pivotal in a promising 4-0 start to 2021.
"If you want to take that next step in your development as a team, you need to deal with injuries to key players," Longmire told reporters on Monday.
"Sometimes it's a few key players.
"It's just part of what AFL footy is ... you have to roll with the punches.
"We've some options there (to replace Franklin and Hickey). Some experience and some youth.
"Form underneath is really important. Because when you get your opportunity, you want to take it with both hands - help us be competitive and help your case, in terms of playing footy."
Midfielder James Rowbottom is on track to return from his knee injury against Gold Coast on Saturday, while Hayden McLean and Callum Sinclair headline the other leading candidates for call-ups.
Sydney will be widely expected to defeat the Suns, but ensuing clashes with Geelong and Melbourne shape as more exacting challenges.
Franklin's earliest possible comeback game is likely to be in round nine against Collingwood, although the 34-year-old is determined to prove club medicos wrong.
"He reckons it'll be two (weeks on the sidelines). We've said three to four, so that probably gives you an idea of where the discussions go," Longmire said.
"We'll see how he goes.
"He's alright, I just had a chat with him.
"Unfortunately it was just a collision-type injury that you can't do much about. That's what happens, hopefully it's only a few weeks and he gets back going again."
Australian Associated Press