Roger Blyth, Chairman of the Ospreys, has hailed Duncan as 'a true legend of rugby in this region', while Head Coach, Steve Tandy, described him as 'the ultimate team man'.
An Ospreys 'original', Duncan made his debut midway through the inaugural 2003/04 season when he featured in a Heineken Cup defeat to Toulouse at Stade Ernest Wallon, since when he has proven to be a mainstay of the region on and off the field for a decade.
He clocked up a century in a 24-23 win over Harlequins at the Liberty Stadium in October 2008, with his 150th Ospreys appearance coming in a 17-6 victory away to Connacht in November 2011.
Prior to the formation of the Ospreys, Duncan had already made an impressive 105 competitive appearances for Neath, first pulling on the jersey in 1998. He made his international debut against Australia in November 2001, and played at two Rugby World Cup's on his way to a total of 57 international caps. There has also been one Welsh Premiership appearance for Tonmawr in 2011, while he has represented the Barbarians on five occasions.
Speaking ahead of his 200th Ospreys appearance this weekend, Duncan commented:
"It's a milestone that you never expect to reach and it creeps up on you. It's an honour to be the first person to play 200 games for the Ospreys but hopefully there will be plenty more people who will go on to make even more appearances in the years to come, including a lot of the boys who are currently in the squad.
"It's unfortunate for Andrew Bishop, who has looked for so long to be the one that got to 200 first before he picked up his back injury. If you look at total minutes on the pitch he's probably played more for the Ospreys than anybody else, I'd say he's certainly played more 80 minutes than anyone. Hopefully he'll be back in action soon and be the next to make 200.
"While I'm pleased to make my 200th appearance this Friday night, I'm more concerned about the team doing well. We've got an important local derby in front of a big crowd and we have to get the performance right. That will always be my priority, ahead of any personal milestone. When you finish playing, that will be the time to look back on all the milestones I've achieved during my career and the 200 will certainly be up there."
Roger Blyth led the tributes to Duncan, saying:
"He is a true legend of rugby in this region, someone loved by everybody. To achieve 200 appearances for the Ospreys, and to become the first ever to do so, is an incredible achievement that Duncan and his family should be justifiably proud of.
"Knowing what Ospreys Rugby means to Duncan, I have no doubt that he will be embarrassed by the attention that will come his way on Friday night and will just want to get out there and get stuck into the Scarlets, but it is only right that we recognise this landmark."
Duncan will be presented with a special commemorative Ospreys jersey by Blyth pitchside ahead of the game, as the players leave their field following their pre-match warm-up.
Steve Tandy, himself an 'original' and a centurion, echoed Blyth's comments, saying:
"He's a special player and it is a fantastic achievement that we are marking, but first and foremost Duncan is a special human being. His durability is his trademark, he's suffered some horrendous injuries but always bounced back and to see him still putting in the kind of performances he is for the region says all you need to know about Duncan.
"I'm fortunate enough to be able to call him a friend, not just a colleague. He's a true Osprey and the ultimate team man who doesn't worry about himself, he puts the team first every time. You only have to look at the work he puts in off the field to help people around him develop and become better players and better people.
"When it comes to working with fellow props it would be so easy for him to hold back, keep his knowledge close to his chest, but you only have to see what he does with the likes of Ryan Bevington, Marc Thomas, and youngsters coming through to understand what he gives this environment. He's always looking to help, and he is well aware of the importance of leaving a legacy. His will not only be the huge amount of appearances he makes for the Ospreys, but the young players coming through behind him who have learnt from him. If he chooses to go down that line I think he'll go on to become an outstanding coach.
"Duncan's honesty is possibly his biggest strength. He isn't afraid to speak his mind and says the home truths when needed, and there is enormous respect for him in the group and among supporters.
"He's a real family man who loves his home region, a fantastic role model, and is desperate to do well for the team."
Another 'original', Rugby Operations Manager Andy Lloyd, added:
"Since day one Duncan has been, and remains, a fantastic asset to this organisation. What strikes me most about him is his selfless nature, always giving to the environment and doing what he can to make it better.
"As a player, I remember how he would always be there to support and assist not only myself but the others in the group, as he wanted people to improve and be the best that they could.
Since moving into a management role I've become even more aware of the hard work he does off the field, giving up his time for the benefit of others.
"His impact as a player has been even greater if that's possible. While always helping others, what drives him is his personal desire to be number one, to be the best. He sets himself the highest standards, and demands the same from everybody around him.
"200 appearances over 10 years is a sign of his durability and consistency. Throw in his games for Neath, plus Welsh caps and you have someone who has been a fantastic servant to the region, to rugby in general and to his country.
"There is some important business to be done on Friday evening, and beyond that, some huge games for the Ospreys, but it's important that we don't overlook this fantastic landmark and what is a great achievement, to become the first Osprey to make 200 appearances."