Nyika, who won New Zealand's first Olympic boxing medal since 1992 in Tokyo last year, beat Louis Marsters by TKO in the second round on the Gold Coast on Saturday night in what was supposed to be his final fight before the Commonwealth Games.
Nyika survived an early barrage from Marsters, before producing a vicious body shot that dropped his Australian opponent to his knees and prompted the referee to wave off the fight, as Nyika improved to a 4-0 record.
However, he struggled to remove his glove after the fight, with an existing issue flaring up and leaving him with his hand in a bucket of ice after the victory.
Before that fight, Nyika fought on the George Kambosos v Devin Haney undercard and was credited with 'best walkout of the night' as he dressed up as Boba Fett for his big entrance, and backed up the walk with a victory.
Meanwhile, boxer Emile Richardson has been added to the team to contest the U75kg category.
The New Zealand middleweight champion hails from Bulls and says he's looking forward to stepping into the ring in Birmingham.
"There's only one goal and that's to win the gold medal," said Richardson.
"I'm really looking forward to being at such a pinnacle event and competing against some of the best athletes in the world."
Boxing at the Commonwealth Games will begin on July 29th and finish on August 7th, with bouts to be held in the National Exhibition Centre.