Long-serving Socceroo and Sydney FC defender Tony Popovic will move straight into a coaching role with the A-League club after announcing his retirement after 20 years at the top level.

A veteran of 59 caps and 12 years with the national team, including the 2006 World Cup squad, Popovic’s retirement will take effect immediately.

The 35-year-old said he made the decision immediately after last Friday’s 2-1 defeat at home to Wellington.

Popovic said that he could no longer perform at the intense level required and will join the Sydney FC coaching staff as an assistant.

“It was a pretty easy decision for me,” said Popovic.

“As an athlete you just know when the time is right, and when you are not getting out of yourself what you can. You want to do it but it is just not there anymore.

“It’s pretty simple for me, at the start of the year I said to myself, `if ever the day comes that I feel I’ve lost control of my destiny or my body that I would stop’.

“For me it’s always been that I’ve got to do things 100 per cent in everything I do, whether it’s training, playing or looking after myself but now I’m not able to do that, that’s what my body’s telling me.”

Popovic would not be drawn on specific career highlights saying he had no regrets and that hardest part of retirement was telling his Sydney FC teammates.

The left-sided defender was an integral part of the Socceroos squad throughout a national team career that was highlighted by a starting berth against Brazil in Munich at Australia’s first World Cup appearance in 32 years.

He also played a key role in the historic World Cup qualification, with a player-of-the-match performance at the heart of the Socceroos defence in the away leg against Uruguay in Montevideo.

Popovic concluded his national team career in spectacular fashion a couple of months after the heights of Germany by scoring with his last touch in a Socceroo shirt in a 1-1 draw against Paraguay in Brisbane.

Along with Brett Emerton and Craig Moore, Popovic is the only player to have represented Australia in World Cups at 17s, 20s and senior level, plus at an Olympic games.

“Tony is an inspirational player who always seemed to be able to bring the best out of the players around him,” said former long-serving Socceroo defensive partner Tony Vidmar.

“He was a very hard worker, very professional and always gave everything in what he did, on and off the field.

“A lot of players looked up to and respected him, senior players and younger players coming through.”

Popovic played nearly 500 matches for club and country in a career that also included lengthy stints with Sydney United, Japanese club Sanfrecce Hiroshima and English club Crystal Palace.

He captained Palace during their Premier league season in 2004/05.

After a decade overseas, Popovic was one of a number of World Cup Socceroos to return to Australia for the 2007/08 A-League season.