Wearing gloves and tracksuit bottoms despite a mild winter's day, the Jamaican did some light stretching, jogging and ball work with the rest of the squad in his maiden drill since being given the chance to win a playing contract by the A-League team.
He showed glimpses of good control, but also some heavy touches, favouring his left foot.
"It's just like track and field -- the first day of training is always the roughest one. You can tell how much work you need to put in. But it felt OK, you know," said Bolt after the 45-minute workout.
The superstar athlete, who also celebrated his 32nd birthday Tuesday, has been given an opportunity by the Mariners despite already trying out with teams in Germany, Norway and South Africa to no avail since retiring from athletics last year.
They hope to turn him into A-League material in time for the start of the 2018/19 season in late October, with the club saying he can stay indefinitely to prove his credentials.
A 70-strong media pack made the trek to the club's base in the town of Gosford, 75 kilometres (47 miles) north of Sydney, to witness Bolt ease into his new life.
The eight-time Olympic champion and the fastest man on earth said he was determined to prove any doubters wrong.
"I'm not setting myself any targets, I'm just going to put in the work," he said.
"This is my first chance to get to a level to play as a professional, so I don't know what to expect. I'm just here to push myself. I'm here with a blank slate, I'm here to learn and get better."
One of the boys
Bolt dominated sprinting since taking double individual gold at the Beijing Olympics in 2008.
He went on to win a further six Olympic golds and pick up 11 world titles before deciding to pursue his real passion -- football.
His love of football began at school, where he was a goalkeeper before moving to centre back, left wing and finally striker.
He would prefer to play up front for the Mariners, promising his trademark lightning bolt celebration if he gets a goal, but said he had no idea where the coach would use him.
"I'm OK on the wing, good at centre forward, but the coach will determine where I play and in what formation. I don't even know," he said, sitting alongside club coach Mike Mulvey.
Asked his first impressions, Mulvey said it was clear Bolt had been nervous, but added: "It's just his first day. He's a fantastic athlete and we're absolutely delighted to have him here with us."
Despite starting a football career at an age when many are thinking about calling it quits, Bolt said he thrived on challenges and admitted in the back of his mind was a dream to play at Old Trafford.
"I daydream all the time about big things," he said.
"One of my biggest dreams is to play for Manchester United, that could be my biggest dream even if it is just for five games, one game, it would be a dream come true because I am a massive fan."