Sydney coach John Longmire's surprise at having superstar Lance Franklin available for Saturday night's win over Fremantle was replaced by the joy of seeing his gun forward back doing what he does best.

Longmire spoke to the media last Monday and ruled Franklin out of the round eight encounter, but sprung a shock when he then picked him in his starting side on Thursday night.

The coach said a positive scan on Franklin's bruised heel on Tuesday allowed the West Australian to train, and he showed his importance with three goals against the Dockers at the SCG.

Longmire said he had no idea he'd have the four-time Coleman medallist available until he proved his fitness on the track later in the week.

"You were surprised? I was a bit surprised (too)," he said.

"He was ruled out on Monday, but the medical staff have always told me it was an unusual injury.

"The phone call came through saying 'would you consider playing him if he got through training?', and that conversation didn't take too long."

Franklin took time to work his way into the game opposed to Joel Hamling and Alex Pearce, but took nine marks to go with his 19 possessions.

"He was a bit rusty with a couple of early kicks but the longer the game went, the better he seemed to feel, and move, and look," Longmire said.

"That’s a good sign and hopefully he pulls up OK."

While Longmire was happy to have Franklin back, he was also impressed with second-gamer Tom McCartin, who added two goals of his own for the home side and has given Sydney a different element in the forward half after debuting against Hawthorn last week.

"(His selection) wasn't about his dominating at the next level down, it was about him competing," Longmire said.

"He's able to bring some of those small forwards into the play just by competing and bringing the ball to the deck.

"He'll start taking some marks as he develops but at the very minimum he's not getting out-marked too often.

"The other guys around him feed off that and he's only a kid, but he's done OK.

"The front half is evolving quicker than most parts of the ground for us."