Sydney have suffered a blow going into the AFL finals, with co-captain Kieren Jack set to miss at least two weeks with a knee injury.

The tenacious midfielder was helped off the ground late in the first quarter of the Swans’ 63-point win over Gold Coast on Saturday at the SCG.

“We don’t know the results, but the initial diagnosis from the doctor is that it’s a medial strain, so two or three weeks,” Sydney coach John Longmire said following the Swans’ 19.13 (127) to 9.10 (64) win.

“He’s going to do everything in his power to give himself the best possible chance – he’s a pretty positive bloke.”

Utility Gary Rohan hobbled off in the final quarter with a knee issue, but Longmire said he expected him to be okay for next week’s clash with minor premiers Fremantle in Perth.

He said Sydney’s other co-captain Jarrad McVeigh would definitely return from a calf injury and expected defender Nick Smith to also come back from a hamstring injury.

The Swans were 31 points up at the time a limping Jack left and they collectively limped through the two middle quarters.

However, they started and finished impressively, with six goals in the first quarter and ten of the last 12, including eight in the final term.

“We dropped off in the second and third terms a little bit with our pressure and our attack around the footy and then we went again in the last quarter,” Longmire said.

“We had 13 tackles to six in the last quarter and we scored eight goals, so when we needed to in the first and last quarter we certainly did it.”

He credited star midfielders Josh Kennedy and Dan Hannebery for triggering the late surge.

Kennedy notched 31 possessions, his tenth straight game of 30 or more touches.

It was Sydney’s fourth straight win and a third successive score over 125 points following 20-goal efforts against GWS and St Kilda.

They had a 38-point lead early in the second quarter slashed to 14 in the third by an understrength but fiercely determined Suns outfit.

The profligate Suns missed at least four decent attempts to make even bigger inroads and coach Rodney Eade lamented the missed opportunities and said they took too many risks in the first quarter,

“It was a disappointing first quarter, we didn’t follow instructions and they got the jump,” Eade said.

“I thought our second and third quarters were terrific and we just ran out of legs. We were just fatigued in the last quarter.”

Swans forward spearhead Lance Franklin tallied 13 possessions, six marks and kicked 1.1 in his second match back from a back injury, kicking his only goal late in the last quarter.

Longmire said he expected Franklin would be better for the run.

Sam Reid and Kurt Tippett grabbed 11 and nine marks respectively and kicked 5.6 between them, with Harry Cunningham and Dean Towers also impressing.

Tom Lynch and Charlie Dixon each kicked two goals for the Suns, with Aaron Hall notching a team-high 30 touches.

The Suns were also forced into a first quarter substitution, with defender Greg Broughton forced off with a hamstring issue in his final game before retiring.