WRU development director Mostyn Richards said, "The Scarlets are just one of several very good sides in this whole competition and to be honest, we have been delighted with the progress the players and their regions have made since the inception of the competition in the summer.
"Lots of things have been said, for and against it, but if you speak to the respective directors of rugby around the regions, you will hear a series of glowing reports. We all believe that the competition is helping to gear our players for the future."
The Ospreys have proven themselves to be a tough nut to crack this season, although they might find the unbeaten Scarlets a little too strong at forward.
Something will have to give in the other game with the Dragons under 16s taking on Blues North at Bedwas. Neither side has won a game so far this season, so picking a winner will be a tough call.
The Dragons have perhaps performed with a little greater success this season but Blues North, coached by Dale McIntosh, will certainly be fired up for the game.