Nathan said there was a lot more to it than how good his first touch was.
"Well at the start they told us that you had to have discipline, respect and you had to be kind. It wasn't all about the skills you had.
" It was about your personality too," Nathan said.
The Papamoa Primary School student said he had a huge lump in his throat when he found out he was the one player selected.
"I was almost crying. It was the most amazing feeling ever. I definitely have always wanted to play for a big club," the Liverpool fan said.
"This has opened a huge gap for me now. It is pretty awesome. I am going to go there to train for a week and also go to Milan Stadium to watch Milan play."
Xavier attends Matua Primary School and plays for Otumoetai Football Club. He trains with the respected Waipuna Coerver Academy based at Waipuna Park.
Before I go, I am going to practise lots, doing stuff at home and with my coaches.
He is renowned for his ability to read a game and coaches regard his game intelligence highly.
Keeping up the hard work and intensity for five days in Wellington was the biggest challenge, Xavier said.
He is looking forward to training with AC Milan, although his favourite team are Barcelona.
"Milan are one of the top clubs in Italy and play in the Serie A League, so for me to train with them is very exciting. They are paying for me to go and either my mum or dad is coming with me.
"Before I go, I am going to practise lots, doing stuff at home and with my coaches."
All-Stars Football Academy head coach and director, Martin Collins, said Nathan would do well in Italy.
"He has a lot of skill. When I picked up Nathan three years ago he was a player who had a lot of promise. He basically has the right attitude and is easy to coach."