The game at St Helens, Swansea (KO 2.30pm), sees the two best sides in the competition meet with a number of players in the Welsh U18 training squad on show.
The Scarlets alone have 12 players selected in the initial Wales squad for their upcoming fixtures against Leicester, France and England though they face a tough task against the unbeaten Cardiff Blues.
Dale McIntosh’s side have won all seven of their games in the competition so far, continuing the success of their regional sides in the last few years. Sunday’s game sees the youngsters from the capital city region play in their fifth successive final.
Despite that record, WRU Performance Manager for the Cardiff Blues Richard Hodges knows his side face a difficult task.
“We all know the Scarlets will be a tough nut to crack,” he said. “It’s going to be a close game as they are a very good side.”
With the Wales side yet to be finalised, a number of players will be playing not just for regional honours but for a place in the national side.
“There are a lot of one on one battles on Sunday and a lot of players pushing for a Welsh cap,” Hodges added.
“It’s almost a game within a game and we know we’re in for a tough test.
“The Scarlets have an abrasive back row and Jack Maynard who has played a lot of Premiership rugby with Carmarthen Quins. Their scrum is also of high quality and we’ll have to get on top in that battle.
“Yes the bigger picture is player development through the player pathway but for 80 minutes on Sunday it will be about trying to win another final.”
The Scarlets themselves have lost just once themselves so far this season and include a number of their recent Wales call ups.
Will Boyde, Josh Adams and Maynard all start with Boyde leading the side from the back row. Maynard partners Gareth Rees at half back with Boyde joined by Josh Middleton and Tom Phillips in the back row in what is sure to be an entertaining and fast paced encounter.
Scarlets: 15 Jamie Evans 14 Lloyd Rogers 13 Steff Evans 12 Morgan Griffiths 11 Josh Adams 10 Jack Maynard 9 Gareth Rees, 1 Bradley Davies 2 Torin Myhill 3 Javan Sebastian 4 Alex Washbourne 5 Josh Helps 6 Josh Middleton 7 Will Boyde (c) 8 Tom Phillips.
Replacements: Ryan Elias, Steff Phillips / Ceiron Evans, Dexter Thomas, Sion Lewis, Lee Taylor, Kieran Hardy, Dan Jones, Dai Treharne.
Blues: 15 Aled Summerhill 14 Ollie Smyth 13 Garin Smith 12 Sam Edwards 11 Jack Huntley 10 Sam Withers 9 Shaun Clarke, 1 Gus Mc Pherson 2 Liam Belcher 3 Dillon Lewis 4 Michael Snook 5 Ben Murphy 6 James Sheeky (c) 7 Matthew Marley 8 Ollie Hitchings.
Replacements: Rob Lewi, Ryan Spriggs, Kieron Belmont, Louie Burley, Bradley Llewellyn, Tom Williams, Tom McAloon, James Whittingham.