After representing Australia in the 2000 Olympic Games but failing to medal, Green turned pro as a super middleweight in June 2001 and won his sixteen bouts before losing to Markus Beyer via disqualification for an accidental headbutt.
But Danny Green would rebound and ultimately win world titles in the Super Middleweight (Interim), Light Heavyweight and Cruiserweight divisions.
Along the way though, the Australian would have to endure the pitfalls that often accompany world class competition and the spoils of victory at the highest levels of the sport.
Green stopped Eric Lucas to win the interim WBC super middleweight title in 2003 but would lose a razor-thin majority decision to Markus Beyer in 2005 in an attempt to obtain the full crown. And after reeling off three more wins, Green dropped a unanimous decision to fellow countryman Anthony Mundine in a WBA Super Middleweight Title Eliminator in 2006.
But persistence eventually paid off for Danny Green. After the loss to Mundine, Green would win ten consecutive bouts over the next five years besting the likes of Otis Griffin (then 18-1-2), Stipe Drews (then 32-1), RoyJones Jr (then 54-5) and BJ Flores (then 24-0).
Perhaps the biggest moment in the Australian's career was his thrilling first round knockout of Roy Jones Jr in December 2009. Although the legendary Jones was unmistakably a bit faded at the time, the bout unfolded only four months after Jones' impressive win over Jeff Lacy - a fight in which many believed Roy had successfully 'turned back the clock.'
After the Jones bout, the Australian successfully defended his IBO Cruiserweight title three more times before suffering back-to-back knockout loses to Antonio Tarver and Krzysztof Wlodarczyk last year.
Today, the 39 year Aussie is about 10 lbs (4.5 kg) lighter and claims to be feeling better and fresher than at any time last year. Nevertheless, Wednesday's cruiserweight clash may be he his final appearance in his home town of Perth where many, if not most, of his 36 bouts have taken place.
"What goes up must come down," Green told news.com.au.
"Everything's got to come to an end. I'm 39 years old and I don't want to fight past my use-by date."
Referencing his late lead on the scorecards (97-93 twice and 96-93) following his knockout loss to Poland's Krzysztof Wlodarczyk on Novemeber 30, 2011, the WBC Cruiserweight Champion, Danny Green stated:
"In my last fight, I was a round away from becoming a world champion for the fourth time, from taking the cruiserweight title from Krzysztof Wlodarczyk. My form in this preparation still suggests I'm not fighting past my use-by date."
"But I know I can't do it forever and I want to leave this game hopefully on top of my game."
Green is hoping for an unlikely rematch against longtime rival and fellow Australian Anthony Mundine but his foe is seeking big and better opportunities for higher-profile bouts in lower weight classes.
With the dim prospects for a Mundine rematch slim, Green may decide to call it quits after facing Santiago later this week.
Green vs Santiago
Nicknamed the "Green Machine," Danny Green insists his preparation for Danny Santiago has been smooth.
"We've approached it far more intelligently.
"I'm a hard worker. It's what I've forged my career on.
"But (Green's trainer) Angelo (Hyder) and I have learned that later on in my career, the longer it goes, my body responds to less work.
"We finished our pad work last night and my brother said to me after: 'That's the best I've ever seen you physically look'. (source: news.com.au)
A journeyman, Danny Santiago, also 39, has won 31 of 37 bouts and recorded 19 knockouts. He sports a draw and all five of his loses have come via knockout.
A year ago, Santiago was dispatched by WBA Light Heavyweight Champion Beibut Shumenov. He's also had back-to-back knockout loses to Antonio Tarver and Zsolt Erdei in 2007.
Santiago, who has a history of falling short against elite opponents, will have his hands full with the reinvigorated, hard-punching Danny Green come Wednesday.
In the end, the question may not be whether or not Green will win. Ultimately, will Danny Green look good enough against Danny Santiago to forge onward and become a fixture again at the highest levels of boxing?