The pair, who are set to feature in opposition in the opening match of the inaugural Rabo Direct Pro12 double-header at the Millennium Stadium, are at different stages of their rugby careers, but are inextricably linked by a unique piece of silverware.
The first title of the new Millennium, in 2005, saw then Blues second row Sidoli play every minute of the campaign which brought the international holy grail of a Grand Slam to Wales for the first time in 27 years.
Three Slams later, the latter of which gave Davies his first Six Nations winners medal in 2012, and the Scarlets centre is an integral part of the squad which, last weekend, ensured Wales retained their European title in back to back seasons for the first time in 34 yrs.
If it all started with Sidoli and company eight seasons ago, the class of 2013 have more than taken on the mantle and arguably eclipsed the much heralded achievements of Wales' sides of the 70s.
But both players remain hungry for even more silverware and they agree that success at international level only enhances their Regional ambitions.
Davies is set to make his 100th appearance for the Scarlets at the home of Welsh international rugby this weekend and feels he has unfinished business with the side he supported as a child.
"I've grown up supporting the Scarlets and the players there are the ones you train with week in week out, so to get a taste of success with them would be particularly sweet," said the 36-times capped Whitland product.
"I've spoken to the Ospreys players when we've been in camp with Wales, they've won this league more times than anyone and they say that winning silverware with your Region is pretty special.
"Success with the Scarlets is definitely something that is important for me, we have a great squad and winning with Wales just makes you all the more determined to reproduce that with your Region.
"We are all determined to put that right with a good run at the business end of the season to get us into the those play-offs and that means putting a performance together against the Dragons on Saturday.
"It will be strange to come back to the Millennium Stadium so soon after the incredible highs of winning the Championship here, but this is a special place.
"The atmosphere is always amazing and if the fans are anything like they were for the England game we should all be in for a real treat."
Sidoli has himself made 96 appearances for the Dragons, he played 42-times for Wales and, after the career highlight in 05 which a 17-year-old Davies watched from the Millennium Stadium stands, last featured at international level in the 62-5 loss to England at Twickenham in 2007.
At 33 he has the edge in experience on the 26-year-old Davies, he knows all about how success at international level can inspire a region and he is looking forward to taking to the Millennium Stadium pitch again for the double-header this weekend.
"The Millennium Stadium is a special place for both the players and the fans and it's a great concept to have these two derby matches here on the same day, the atmosphere will be amazing," said Sidoli.
"We've seen how well this Welsh side has done and enjoyed watching them. It lifts everyone mentally to see Wales do well and the players who have returned to train with the Region have really boosted us and I think we have a role to play in energising them as well.
"It can be draining to achieve success like they have done, certainly in 2005 it was the first time anyone had experienced that kind of success for a long time so we were on the ceiling for a good while afterwards.
"This squad has managed to sustain their success now so the next step is to reflect that in the regional game.
"This will be a big weekend for all four sides, just as we have been a bit of a thorn in the side for the Ospreys in recent times the Scarlets have probably been that for us.
"We know we can be a dangerous side but we have been inconsistent. The challenge for us is to be consistently dangerous and put some performances together to be proud of during the season run in.
"The Millennium Stadium is a great stage to play on and it should inspire some great rugby this weekend, with us all hopefully picking up where the national team has left off."