Bolt's "indefinite" training period with the Mariners kicked off at Central Coast Stadium in front of a media contingent that numbered almost 100.

A 15-minute passing drill, which Bolt completed without any terrible gaffes, was coach Mike Mulvey's only chance to judge the Jamaican sprint superstar's footballing skill.

A trial game on August 31 shapes as Bolt's likely debut but Mulvey won't rush his decision on whether the eight-time Olympic gold medallist deserves a contract.

"If it takes 12 months, I'm happy for him to be here," Mulvey told reporters.

That sort of backing is part of the reason that Bolt, who still dreams of playing for Manchester United, chose Gosford as the base for his bold bid to become a professional footballer.

"We got offers from teams in Spain, France and stuff like that," Bolt said during a 20-minute press conference that covered topics ranging from Central Coast's nightlife to his primary-school goalkeeping career.

"But for me it'd be harder because you have to learn a new language, it wasn't in the top division.

"Australia is somewhere I enjoy coming ... this is a start and I'm really appreciative of everything the Mariners have done.

"I look forward to scoring as many goals as possible and bringing home the trophy, but I'm just trying to get over the first hurdle now, that's to get a contract."

Bolt, who said he is "good at centre forward but open to playing anywhere on the park", vowed to respect Mulvey's final decision regarding a contract.

It's been just over a year since Bolt retired from athletics. He has previously trained with clubs in Germany, South Africa and Norway without being offered a contract.

Bolt conceded he was out of his comfort zone on his 32nd birthday, and not just because of the chilly wind and baking sun.

"It's just like track and field. The first day of training is always the roughest one," he said.

"You can tell how much work you need to put in but it felt OK."

Bolt tuned up for his stint by training with a Jamaican club, thanks to his relationship with former Bolton player Ricardo Gardner, but is a long way off peak condition.

The 100m world record holder regularly mopped his brow and put hands on hips as fatigue kicked in during the hit-out.

The bulk of the squad took part in a simulated match drill while Bolt did exercises under the watchful eye of Andrew Young, the Mariners' head of performance.

"I have to get fit," Bolt said.

"I'm ready to work. I know it's going to take time."

Australian Associated Press