ADAM Goodes is irreplaceable according to Sydney Swans co-captain Jarrad McVeigh, who has no doubt the decorated veteran is playing well enough to go around again next season.

Saturday's grand final looms as the potentially perfect swan song for the 34-year-old forward, who will swell to 351 his club games record.

If the Swans win, he becomes the club's first three-time premiership player, and could retire with a swag of individual awards and widespread admiration of his many on-field accomplishments.

Goodes, who played his first senior game back in 1999, says he won't make a decision until after Saturday's game.

He doesn't have the stamina to dominate matches as he once did, but remains a more than handy role player.

Goodes has contributed 28 goals this season, behind only Coleman medallist Lance Franklin (75) and Kurt Tippett (33).

His three-goal effort in last week's preliminary final win underlined how he is still capable of impacting a game in pivotal moments.

Goodes kicked a momentum-changing goal in each of the first two quarters, after North Melbourne bagged the first major in both of those terms.

"We saw last week how good he played," McVeigh said on Thursday.

"I've got no doubt he could play on, but we're not even really thinking about that this week.

"We just want to play the right way this week and I'm sure he wants to put in another good performance."

McVeigh, who shared the captaincy duties with Goodes in 2012 and 2013, stressed the Australian of the Year's value to the Swans extended well beyond the boundaries of the grounds he has graced for so long.

"You can't measure it, it's been unbelievable," McVeigh said.

"When he decides to retire, no-one can replace Adam Goodes.

"Two Brownlows, two premierships, three best and fairests, countless awards.

"We all know what he's done.

"But more of a friend - he's been an unbelievable friend to a lot of us, so he cannot be replaced."