"The players who are at this level are very committed," he said. "They travel a lot for training and playing."
The National Training Centre is held twice a year, in the April and October school holidays.
Thirty players are selected in each age group from the Waikato and Bay of Plenty, Auckland, and Northern football federations.
Alabaster said the players were rated throughout each training and about 10 players with the lowest ratings were dropped from the programme. The remaining players from around New Zealand are then included in the New Zealand Under-17 squad, which plays in the Fifa Under-17 World Cup.
All nine of the players play for North Force age-group teams and regularly compete in Auckland leagues.
"Every second week, they're playing away," Alabaster said.
The selections come two weeks after Northland Football history was made, when the North Force Under-16 side won an Auckland Football Federation metro league. Rungpao was the only player from that team to make it through to the training centre.
At the time, coach Dan Johnston said the representative team had exceeded his expectations.
"I still can't believe we won it," he said. "It hasn't sunk in yet, I have to look at the league table to believe it."
The team's success, losing only one game in the league, and the large number of players now on the path to a national level show a promising future for football in Northland.