The North, who were 10-3 winners against the Dragons last week, entertain the Scarlets at Abercwmboi, whilst the Ospreys, who defeated the Scarlets in their opening game, take on Blues South at Llandarcy.
Brad Llewellyn takes over from Jack James as captain of a North side that shows nine changes to the team that pipped the Dragons at a rain-sodden Abercwmboi. The Scarlets are also much changed - only eight players remain from the side beaten by the Ospreys, on home soil, two weeks ago.
At under 18 level, the Blues and Scarlets meet at Parc y Scarlets with both sides having won once aleady this term. The Scarlets, who were outstanding in defeating the Ospreys, will be looking to gain revenge for last season's final defeat by the Blues. Jordan Williams was in excellent touch against the Ospreys and he might, once again, be the key to the home side's hopes of downing last season's champions.
The Scarlets, led by full-back Luke Treharne, make four changes to their side while the Blues make seven alterations to the team that hammered RGC 1404 at Merthyr on August 15.
Without a game last week after their scheduled derby clash with the Dragons at Rodney Parade, was postponed due to heavy rain, the holders will certainly have their work cut out on this occasion.
Blues North under 16s: C Lawrence; O Smyth, S Edwards, G Smith, J Barnett; J Evans, J Harris; D Lewis, N Evans, K Belmont, A Luxton, M Jezalik, J Allen, I Evans, B Llewellyn (capt). Replacements: A Gibbs, J Smedley, A Panniers, J James, S Clarke, J Jones, A Gwynne
Scarlets under 16: J Evans; J Barnes, S Evans, C Woodall, M Davies; J Maynard, I Bowen; B Davies, E Lewis, C Evans, J Helps, A Washbourne, C Randell, W Boyde, L Taylor. Replacements: J Sebastien, T Myhill, L Watling, T Phillips, G Kenniford, G Rees, J Adams
Ospreys under 16: A Rowlands; J Needs, M Burnbell, J Thomas, D Howells; J White, D Brooks; L Jonathan, J Williams, D Owens, T Lewis, R Morgan, B Evans (capt), C Leyshon, C Davies. Replacements: G Stone, M Parmenter, A Williams, L Cox, T Maggs, L Popham, J Anderson, J Seldon, T Williams
Scarlets under 18s: L Treharne (capt); J Randell, D Jenkins, G Owen, A Evans; J Williams, R Williams; B Allsop, T Ball, T Kaijaks, C Marks, D Morgan, S Bennett, D Thomas, J Williams. Replacements: S O'Leary, T Evans, G Davies, C Morris, O Powell, C Lloyd, N Setaro
Blues under 18s: C Allen; H Robinson, R Evans, T Pascoe, O Jenkins; R Patchell, J Raikes; T Davies, J Dando, B Thyer, B Roach, C Lacey, J Sienawski, E Jenkins (capt), L Young. Replacements: J Hopkins, C Lewis, L Connolly, S Pring, L O'Brien, G Thomas, J Phillips
Fixtures (kick-off 7.15pm)
Blues North v Scarlets (Abercwmboi)
Ospreys v Blues South (Llandarcy Academy)
Scarlets v Blues (Parc y Scarlets)