Zac Guildford says he is ready to put his troubled past behind him and repay the faith Waratahs coach Daryl Gibson has shown in him.

The former All Blacks wing was handed a lifeline with the Waratahs after returning to New Zealand on the back of a short, unsuccessful spell with Clermont in the Top 14. He has since opened up about what triggered his bad behaviour and disciplinary issues in the past and stated he's ready to shake off the bad-boy tag.

Guildford's dad, Robert, suffered a heart attack and passed away in the stands while his son scored two tries to guide New Zealand to the U20 World Cup title in Tokyo in 2009. 

'I went from jubilation and then five minutes later I found out that my dad passed away, and I'm looking in the stands and my mom's crying. It was difficult to go from such a high to such a low and I never really got to celebrate that win with the team,' he said.

'I messed up big time. I used my dad's passing as an excuse for a long time, but I can't keep using it until I'm 40. I need to make my dad proud now and play some awesome rugby and by doing that I'll bring peace to him and the rest of my family.'

The 26-year-old, whose problems were mostly alcohol related, says he is tired of making the same mistakes.

'I'm over it, to tell you the truth. I can't say I'll never drink again, but for the moment I'm happy not doing it.'

About his move to Sydney, Guildford admits that while there was interest from other Vodacom Super Rugby teams, Gibson convinced him to commit to a 10-month contract.

'Gibbo came over [to New Zealand] and it showed me that he wanted me as a rugby player to be part of an organisation, but also that he actually cared about me outside of rugby. It's pretty cool that we can connect on a personal level and hopefully transfer it into rugby.'

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