Sydney champion Adam Goodes has announced his retirement from AFL following the Swans' 26 point loss to North Melbourne in the semi-final on Saturday night.

Goodes told his teammates of his decision behind closed doors shortly after the loss.

Coach John Longmire said Goodes did not want a lot of fan fare.

"I was a bit emotional but he was fine, he handled it really well, so he'll take a deep breath now and he needs it," Longmire said post-match.

"(He) just (said) how he's been able to enjoy 18 years at a great football club, and the relationships he's been able to establish over a long time, and how everyone means so much to him.

"It's probably hard to imagine life without the footy club but he'll be right, he's pretty successful in whatever he does.

"It's probably been pretty settled in his mind for a while, he's kept it to himself really well because it's never really been about Adam, he's wanted to make sure it was about the season and trying to be competitive as long as we could.

"As great as what he is and has been for this football club, football club's move forward and that's always been the case," Longmire said.

"No matter how many great players we've had retire, and we've had a few over the past few years, none as great as 'Goodesy' with no disrespect to the others.

"He's been an absolute icon of this footy club, and a superstar of the game.”

Goodes played a club record 372 games for the Swans in a career that yielded two premierships, two Brownlow Medals and four All-Australians.