A
Manawatu representative, Whakarau moved south in 1986, joining the Upper Hutt Tigers and played till the 1991 season
Wellington Rugby League and becoming a
Wellington representative. Sonny first went to the UK in 1991 and played for Batley Rugby League club, he then got signed by Bramley Rugby League club by former Great Britain Rugby League coach Maurice Bamford and had two successful seasons there in 1992 and 1993, In the 1994/1995 English season Whakarau joined
Doncaster and helped them win promotion to the First Division under the coaching of former Welsh and Great Britain hard man Tony Fisher. He played for the
Sheffield Eagles in 1995/96 season. Whakarau represented
New Zealand Māori at the
1996 Pacific Cup and then played in their defeats of
Papua New Guinea and
Great Britain the same year. He played for the
Wakefield Trinity (Wildcats) in 1998, and 1999. Whakarau then returned home and played for the Levin Knights and
Manawatu. In 2000 he was appointed
player-coach of the Manawatu team but handed the coaching reins over to former coach Paul Sixtus after one game. He was later appointed the
Manawatu Rugby League development officer, in 2001. In 2002 the
Central Falcons were admitted to the
Bartercard Cup and Whakarau became a regular in the side, playing close to 50 games over the next three seasons until his retirement from representative football at the end of the 2005 season. In 2004 Whakarau played for the Levin Lions in the Western Alliance club competition. Whakarau was selected for New Zealand Māori as part of the
2004 Pacific Cup squad.{{cite book ==References==