SYDNEY Swans star Lance Franklin has failed to recover from a back problem and will not take on Collingwood at the SCG on Friday night.

The Swans had hoped to regain the three-time Coleman medallist for the crucial clash with the Pies, but he was ruled out by the club's medical staff after failing to take to the track with his teammates on Wednesday.

Franklin missed last week's 32-point loss to Geelong and has been struggling with the back injury since being a late withdrawal from the Swans' clash against West Coast in round 17.

The 28 year-old played the following week against Adelaide in support of missing teammate Adam Goodes, who was on personal leave, and even though he kicked three goals, Franklin struggled throughout the match.

While the injury isn't a threat to Franklin's season, the lingering problem is starting to frustrate the forward, according to Swans general manager of football  Tom Harley.

"If there's one thing I know about Lance is that he’s a competitor," Harley told the club's website.

"We were hopeful that Lance would get up this week but he has not been able to get over the appropriate hurdles so he will have another week on the sidelines."

In better news for the Swans, Gary Rohan (hamstring), Mike Pyke (knee) and Ben McGlynn (hamstring tightness) could be a chance to face the Pies after getting through training on Wednesday.

All three will need to be assessed again before the Swans pick their team on Thursday.