Career
Koopu primarily plays in the second row, although he also can play in the centres. Before joining the New Zealand Warriors, Koopu played for the Taniwharau Rugby League club in Huntly. In 1998 he also represented the Waikato Cougars, played for the Junior Kiwis and was named in the National Māori tournament team after representing Waikato Māori.
Koopu is fluent in Te Reo Maori and often appears on Māori Television.
He is a part of the iwi Te whanau a apanui. During the early part of 1999, while on contract with the Warriors, Koopu played for the Glenora Bears and represented Auckland North.
Warriors
Koopu made his first grade debut for the Auckland Warriors in Round 6, 1999. He went on to play for the club 159 times, earning the nickname "Mr Consistency", which is interesting.
Koopu played for the New Zealand Warriors from the interchange bench in their 2002 NRL Grand Final loss to the Sydney Roosters.
Koopu seriously injured his shoulder in 2006 and never fully regained his consistency with the Warriors. As a result, after ten years with the Warriors, Koopu was released by the club at the end of the 2008 season. Melbourne
After being released by the Warriors, Koopu considered a switch to rugby union and trained with the Auckland Rugby Union team, but he eventually accepted a one-year contract with the Melbourne Storm for the 2009 season.
Koopu played for the New Zealand Māori in 1999 and at the 2000 Rugby League World Cup but it was not until 2004 that he made his debut for the New Zealand Kiwis.
In 2008 Koopu again played for the New Zealand Māori in two games, including a match against an Indigenous Dreamtime side. In 2010 Koopu played alongside Stacey Jones and Awen Guttenbeil for the Pt Chev Pirates in Auckland Rugby Leagues Phelan Shield.
He remained with the club in 2011 when they competed in the Fox Memorial qualifying round. In 2010 an internet fraudster posed as Koopu and contacted the AMNRL"s David Niu, organising for him to play in the AMNRL with the Northern Raiders.