John Jones, Lloyd Elliott and Tom Williams (2) were on the try trail last time around for the U18 and they will fancy their chances against a Dragons side coached by senior stars Jason Forster and Gareth Baber. They were beaten by the Blues last time out at Sardis Road.
The U16 will be without wing Brett Pritchard - he broke an ankle in last week's victory, so the Ospreys will need to make at least one alteration for the visit of Blues North. Jason Jones, Rhys Roberts and Rory Pitman crossed for tries last time out, whilst Daniel Biggar, in his second season with the side, adding one conversion.
The U16 Scarlets make the long trip to Cardiff to play Blues South, whilst the U18 entertain the Blues tomorrow at Stradey Park. Both are looking for their first win of the season.
Blues South v Scarlets (Llanrumney Field)
Ospreys v Blues North (Corus)
Scarlets v Blues (Stradey Park)
Dragons v Ospreys (Virginia Park)