SYDNEY Swans co-captain Kieren Jack's 2015 season could be over after the midfielder suffered a knee injury in his side's 63-point win over Gold Coast on Saturday night.

Swans coach John Longmire said the initial diagnosis from club doctors was that Jack could miss 2-3 weeks with a medial ligament strain in his left knee, meaning that unless the Bloods make the grand final, the tough on-baller is done for the year.

It's a massive blow to the Swans' chances of beating the Dockers in Perth next Saturday afternoon, with reigning club champion Luke Parker already ruled out with a broken leg.

Five talking points: Sydney Swans v Gold Coast

The worst possible scenario could see Jack not play again this season unless the Swans make the grand final, but Longmire hasn't given up hope of having his leader back on the field sooner rather than later.

"You get an injury around your knee at this time of the year (and) you're not doing cartwheels, so he wasn't too happy about it. But that's football and he's going to do everything in his power to give himself the best possible chance," Longmire said.

"He's a pretty positive bloke, he'll go about his rehab now and give himself every chance."

There was more positive news for the Swans with Lance Franklin and Gary Rohan both playing a full game against Gold Coast.

Rohan finished the match with ice on his knee but Longmire said it was purely precautionary.

Franklin didn't look to be 100 per cent fit against the Suns, but the star forward did enough to put a smile on the face of his coach.

"We knew that he needed another game. He trained this week fully and he'll train next week and play," Longmire said.

"We think he'll get better as he goes. I'm not sure if he's at his absolute best but he takes an important player and it doesn't take a lot of chances for him to have shots at goal.

"He's got class on his side and he gets around and has another week of training and he'll be better for that again."

 

A real positive for the home side was the form of fringe players Dean Towers, Harry Cunningham and Jake Lloyd against the Suns.

Lloyd was recalled to the side this week to replace injured defender Nick Smith, while Towers got a late call-up when co-captain Jarrad McVeigh withdrew from the 22 on Friday.

WATCH: John Longmire's full media conference here

Cunningham kicked three goals and had 18 possessions for the winners, while the versatile Towers had 20 and grabbed two goals. Lloyd finished the night with 10 marks and 20 touches, and Longmire was impressed with the contribution of his lesser lights.

"It was good to see Towers come in and make a real impact. Harry Cunningham has been kicking goals and playing a number of different roles for us for quite a few weeks now," Longmire said.

"It was good for Dean (Towers) to get a run. He did quite well across half-forward and really pressured hard and provided another option in our front half.

"We've played a fair bit over the course of this season with our players in different positions, we wanted to add some flexibility to our team over summer and we've done that all year, and will continue to do it next week."

Kieren Jack looks on from the sidelines on Saturday night. Picture: Getty Images

Longmire said he expected McVeigh to return for the trip to Perth, with Smith (hamstring) also rated a chance to face the Dockers.

Experienced duo Ben McGlynn and Craig Bird both played well in the NEAFL on Saturday, so the pair will also be in contention for next week's final at Domain Stadium.