AN INJURY-HIT Sydney "desperately needed" Lance Franklin to play last weekend despite him being bed-ridden in the days before the Swans' defeat to Fremantle at the SCG.

Coach John Longmire said the decision to pick a "really sick" Franklin was due to Sydney's growing injury list, leaving him with no other choice.

"I spoke to him (Franklin) Friday afternoon at 4.30 and he had spent all day in bed, he wasn't going to play," Longmire said.

"And just because of the competitor he is, and knowing that we didn't have any other options, he said, 'I'd like to play'."

Franklin struggled during the side's defeat against the Dockers last Saturday with the forward failing to kick a goal for the second consecutive week.

It's the first time in a decade one of the AFL's greatest players has failed to goal in back-to-back games.

"Clearly at 36 it's a challenge for him, but he knows that we desperately need him. We desperately need him at the moment," Longmire said.

Marc Sheather (foot) has joined Callum Mills (calf) and Logan McDonald (ankle) on the injury list for this weekend's match against North Melbourne while Tom McCartin is set to miss at least another week due to concussion, although ruckman Peter Ladhams (arm) should return.

All told, the Swans currently have their three best tall defenders, three tall forwards and best midfielder in the casualty ward, which has forced Longmire to make 21 changes to his team through nine rounds this season.

Key forward Aaron Francis was in line to start in Franklin's position last week, but Longmire made the decision to play him down back, where the Swans are missing the McCartin brothers and co-captain Dane Rampe.

"In our VFL team, all of our forwards were of 180 centimetres," Longmire said.

"There was no one else.

"For him (Franklin) to be able to climb out of bed last week and get on the footy ground was just extraordinary."

The 2012 premiership coach urged people to moderate their expectations but dismissed talks around whether Franklin was a spent force, having played on for longer than he needed to.

"His ability to be able to play like he did 10 years ago, I think everyone has to sit back and just understand that that's not the case. The expectations have to be adjusted," Longmire said.

"He knows that we need him out there, and we love him at his very, very, very best.

"But there's also an understanding that whatever he can give us is something that we're really fortunate to have.

"And our team sports to be able to have a player like Lance be able to get out there and give us whatever he's got, and understanding that whatever he's got, is a real bonus for us.

"The realistic opportunity for us at the moment is we need him playing and he's doing everything he can to get himself right every week to get out there."