The Philadelphia Union starlet signed for City last year and will formally move to the Premier League giants in 2027 when he turns 18 years of age.
Meanwhile, during this summer break, Sullivan has taken advantage to enjoy a training and playing stint at City.
In a friendly against Buxton FC (England's sixth tier), he impressed: coming on in the second half, he scored after just 16 minutes with a powerful left-footed shot to the near post. A flash of brilliance that confirms the expectations placed on him.
An U17 international with the USA, Sullivan still has three national teams to choose from: the United States, Germany, and Bangladesh. But his dream is clear: "I want to play in the 2026 World Cup in my country, even if I'm only 16. That would be crazy."
Left-footed and 5'7", Sullivan describes himself as a "playmaker" with great vision and dribbling ability.
His idol? "Messi. I've been watching him ever since I learned to use YouTube."