Losing co-captain Phil Davis for the season has been rated a massive blow by Greater Western Sydney heading into the most significant Sydney AFL derby yet.
The 10th-placed Giants are six points off eighth and need to win all three of their remaining games to have any chance of making a maiden finals appearance.
The Swans believe they will have to do likewise to move up one spot and displace the Western Bulldogs from fourth position.
Giants' key defender Davis strained his hamstring in the second quarter of the away loss to Port Adelaide last Sunday.
"It's (a) huge (loss), he's been massive for us," midfielder Ryan Griffen said.
"He's had his ups and downs over the years, but he was playing some really consistent footy early for us, so for him to go down again it hurts."
Davis becomes the third Giants star to be ruled out for the season following ruckman Shane Mumford (ankle) and key back Tim Mohr (knee).
Griffen said he hadn't yet got any messages asking for a favour this weekend from his former club the Bulldogs.
"No I haven't, but it's a massive game for us as well," Griffen said.
"It's a do-or-die game for us if we want to make finals.
"I know all the young boys, they want to have their first finals appearance and we're looking to go out there and get a good result."
The Swans are also approaching Saturday's Spotless Stadium encounter with a must-win mentality, as they are level on points with the Bulldogs, but behind them on percentage.
Swans' midfielder Josh Kennedy, who has played in all seven previous Sydney derbies, stressed there was more on the line this week than the usual intra-city bragging rights.
"This one in the context of the season certainly for us is really important," Kennedy said.
"We want to get a top-four spot and we feel that we have to win every game from here on in to get that and we need things to go our way as well, with teams ahead of us."
Sydney have also lost a key player this week, with midfielder Luke Parker ruled out for at least four games with a broken fibula.
"I guess from the team's point of view we can't dwell on it too much," Kennedy said.
"We've got to try as best as we can to get around him and win this weekend and give ourselves the best chance to continue late in the year.
"Who knows? He might be back if we give him a chance, so that's really go to be our focus now."