Madder is one of three Central Boys Under 18 players in the 39-strong squad, alongside fellow midfielder Sean Findlay and goalkeeper Luke Elmes, both 17, with Elmes one of five goalies in the group.
Their team finished runnerup at the national tournament, narrowly losing 2-1 in the final to Canterbury, who had ten players named in the New Zealand squad.
These Under 18's squads do not contain players in this age group who have already been chosen for the Vantage Black Sticks or the NZ Development squads.
Madder has a big game tomorrow with his Whanganui men's team in Hockey Manawatu's Premier Group B with their round robin match against Palmerston North Boys High at the Twin Turfs.
PNBHS drew level with Whanganui on the points table after their 3-1 win over College B on Monday evening in a deferred match from last Saturday.
Both teams want the win for the chance to join HSHC A in making the championship final, was well as earning automatic qualification into Premier at the start of next season.