Heavyweight David Tua says his family will be his motivation when he steps in the ring for his rematch with American Monte Barrett in Auckland tomorrow night.

The pair fought out a controversial draw in New Jersey in July last year, when Tua was knocked to the canvas for the first time in his career.

While Tua will need to beat Barrett to retain hopes of another shot at a world title, he said today it would be the thought of his family that would spur him on in the rematch.

"I've got a family to look after," he said.

"It's not just about winning fights any more, It's about living. A living for me is about doing the best thing I can do at home. That's the only thing that matters to me."

While Barrett was the heavier in their first bout, he weighed in today almost 10kg lighter than Tua, who was at 110.8kg.

Tua, 38, declared himself ready for the 12-round contest, but wasn't predicting how things would go.

"I'm looking forward to a good fight, a good test," he said.

"I'm prepared for anything."

The Samoa-born New Zealander goes in with a record of 52 wins (43 by knockout), three losses and two draws.

Barrett, 40, has 34 wins (20 by knockout), nine losses (five by knockout) and two draws.

By most accounts, he should have one more win to his name, but for the judges' decision to score his previous clash with Tua a draw.

Tua admitted today that he thought he had lost the fight at Atlantic City.

"In my heart of hearts I think I did, without a doubt."