Those who have made it into the regional squads have fought off stiff competition and will now be looking to impress as the tournament kicks-off.
Blues head coach Matt Silva is particularly pleased to see the start of the competition ahead of his side's clash with the Dragons.
"We're really pleased to see the tournament begin," he said.
"The boys have worked hard, sometimes training three times a week so there's been a lot of effort and commitment gone in to get this far.
"We've worked hard on fitness and want to play an expansive, fast-flowing game."
This style of play was in evidence in a pre-season which saw victories over Leicester and Blues North and a narrow loss to Northampton and Silva believes his team is ready to go.
"All in all, preparation has gone really well and the boys are relishing the challenge," he added.
"We don't know much about the opposition but we do know they will be very committed and physical as Dragons sides usually are so we'll have to match them in that department."
For the Dragons, pre-season has gone equally well with a win over Leicester and a draw against the Scarlets.
"Preparation has gone really well but having played the Blues South last year they will be a quality unit and very skillful," said Dragons coach Grant Robson.
"It's going to be a tough and competitive fixture, especially as it's an away game for us."
At Llandarcy, the Scarlets face a tough task against the Ospreys who have a good record against them in recent years.
"The Ospreys usually start well and they've beaten us first time up in the last few years," said Scarlets performance manager Kevin George.
"We've placed an emphasis on starting well this year. They've always got a big team but we offer something different."
"We think we've got the makings of a good squad but after the first round of games it will be interesting to see who the power forces are."
Blues South XV against Dragons: 15 Josh Thomas 14 Josh Rodgers 13 Teri Gee 12 Nick Griffiths 11 James Walsh 10 Luke Fish 9 Liam Free, 1 Sam Brinkworth 2 Aldi Coverdale 3 Joel Ringer 4 Will Beeching 5 Tom Hayward 6 Dan Holder 7 Harry Dowell-Bennett 8 Sid Blackmore (c). Replacements: Will Haines, Matt Holder, Theo Warren, Cengizhan Ziyaeddin, Cameron James, Myles Churcher, Alex Guard, Rhys Savory.
Dragons XV against Blues South: 15 Arwel Robson 14 Lewis Phillips 13 Barney Nightingale 12 James Hussey 11 Patric Lewis 10 George Collins 9 Owain Leonard, 1 Jack Kedward 2 Jack Davies 3 Jack Williams 4 Bryce Morgan (c) 5 Ben Watts 6 Lloyd Phillips 7 Dawid Rubasniak 8 Matthew Donovan. Replacements: Corey Greenaway, Jack Johnsey, Angus Brown, Ryan Collins, Max George, Sior Pearce, Connor Edwards, Jarred Rosser.