Sydney's AFL season was jolted into a perspective beyond sport after its head trainer died after suffering a massive heart attack during the Swans' six point loss to the Kangaroos at the SCG.

Sitting on the bench, Wally Jackson, who started with Sydney in 1991, collapsed by the players' bench 15 minutes into the last quarter, said football director Andrew Ireland, the only Sydney player or official to front the post match media conference.

"He's been one of those blokes who is extremely important to the players," Ireland said.

"As head trainer he had a special relationship with the players, as well as working hard with them to get them out on the ground, there were a lot of them that were particularly close to him.

"His wife died not long ago and every player on the list went to the funeral.

"So they hold him in very high regard and obviously they are pretty devastated by it."

Players running to and from the bench would have been aware what was going during the final term in which Sydney squandered a 40-point lead.

"But as soon as the game had finished it seemed most of them had understood what had happened," Ireland said.

The Swans media spokesman Stephen Brassell later released the following statement.

"Despite the best efforts by the Sydney medical staff and the staff at St Vincent's Hospital he was pronounced dead on Saturday night."

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