Usain Bolt is trying to launch a career in football.

Usain Bolt is on the verge of sealing a deal to trial with the A-League's Central Coast Mariners, the Australian club said Tuesday (Jul 17), as the sprint legend pursues his dream of playing professional football.

Eight-time Olympic champion Bolt, 31, who retired from athletics after August's World Championships in London, is an avid Manchester United fan who has long dreamt of playing top-flight football.

The 100m and 200m world record-holder trained with Norwegian club Stromsgodset last month and Bundesliga club Borussia Dortmund in March.

The planned arrangement will see him take part in a six-week trial starting next month at the Mariners' base in Gosford, some 75km north of Sydney, chief executive Shaun Mielekamp said.

A season-long deal could follow if it goes well, he told commercial broadcaster Channel Seven.

Football agent Tony Rallis, who has been working on the deal, told Sky Sports Radio's Big Sports Breakfast Tuesday it has been agreed "in principle ... subject to a couple of benchmarks".

"Mainly, a trial, and of course marquee funds support from (governing body Football Federation Australia)," he said, adding that the arrangement was not a gimmick.

"Once the FFA comes back and says that they'll be part of the process, we're going to the trial ... This bloke's an ambitious athlete. The A-League needed a hero, and we got superman."

Mielekamp said his club had been working on the agreement for four to five months, and there was still "some work to do".

"But fingers crossed things might play out, but the most important thing is we wait to find out and see how good a footballer he is first.

"If all goes well, who knows? He may be playing in the A-League this season."

Mielekamp said reports of Bolt's performance at the European clubs he has trialled with have been "pretty good", and that "every time he trains, he improves significantly".

"He has a very good left foot, and time will tell at what level he is at and if it fits the A-League ... it would only be big if he could play and go really well," he said.

"If he comes in and he is not up to the level, it could have a detrimental effect."

Bolt has dominated sprinting since taking double individual gold at the Beijing Olympics in 2008. The charismatic sportsman went on to win a further six Olympic golds and pick up 11 world titles.

The A-League season starts in October.