The Mariners want to bring the champion Jamaican sprinter down under to play in the 2018/2019 season.

Football agent Tony Rallis, who's clients include Central Coast coach Mike Mulvey and players such as Socceroo defender Trent Sainsbury, is behind the Bolt deal.

Rallis told FourFourTwo that it is not a gimmick and that he has been working on the deal for the past three months.

The Mariners will need to tap into the FFA's marquee player fund, for an amount believed to be up to $900,000, to get the Bolt deal confirmed.

Both Mariners owner Mike Charlesworth and Mulvey are supporting the play for the 31-year-old Olympic gold medallist, who will go on a six-week trial at the club with the opportunity to win a contract.

Rallis said Bolt is not guaranteed a contract at Gosford and will have to earn it on trial.

"I would like to think that if this gets supported the A-League will be put on the map," he said.

"Hopefully the FFA will support it. I just want to help the game, I really do. We need to do something.

"Usain will trial, if he fails then there will be no contract. The world will talk about the A-League in the meantime.

"Usain is committed to being a footballer. He will attract a new supporter base. What he brings by way of new media platforms, a new supporter base and corporate deals will be second to none."