All over: Brett Emerton played 95 times for the Socceroos.

All over: Brett Emerton played 95 times for the Socceroos. Photo: Getty Images

Australia's third-most-capped Socceroo of all time, Brett Emerton, will announce on Thursday that his 18-year professional career is over.

The club will host a media conference to formalise the end of a journey that has taken him to the heights of the game for club and country.

When news of Emerton's decision broke on Wednesday, the club decided against making any comment, preferring to wait for the official announcement.

Emerton, 34, has laboured through a difficult final season at Sydney FC and was taken off after just 52 minutes in last week's Sydney derby, citing a back injury.

He has been battling a chronic complaint for the past six months and despite repeated attempts to overcome the problem it has clearly restricted his output.

The writing was on the wall for Emerton in the aftermath of the 1-0 derby defeat, with coach Frank Farina all but conceding his Australian marquee player was losing the battle with injury.

Emerton, who hails from western Sydney and still lives in the area, looked disconsolate after being substituted. "He didn't carry anything [injury-related] into the game but it's well documented Brett's had issues with his back and he said at half-time it was tightening up again," Farina said.

"His back has been giving him problems for a couple of years and I've known Brett long enough so that when he says something is wrong, it's just better to take him off."

Emerton has endured a tough finish to an otherwise brilliant career, one which took in successful spells at Dutch giant Feyenoord and English club Blackburn Rovers after starring in the National Soccer League with Sydney Olympic.

At a time when young players were in a rush to head to overseas leagues, Emerton didn't leave until he was 23, establishing himself as a genuine star of the local competition.

Once Emerton broke into the European game he was an instant hit in the Netherlands and gained a winner's medal from the club's UEFA Cup run in 2002, moving to the English Premier League a year later.

After he racked up almost 300 appearances in all competitions during a nine-year spell with Rovers, it was a surprise when he quit the English Premier League in 2011 to sign with Sydney FC.

But things never quite worked out as hoped on his return, though he did manage to captain the A-League All-Stars against Manchester United in July last year, a moment he described as a "huge honour".

His career ends on 95 international caps, five short of the milestone he craved, and which he hoped to reach at some point during the 2014 World Cup.