The Arms Park youngsters will start the game as favourites after defeating the Welsh All Blacks in two league clashes and Cardiff secured the league title last weekend after their 26pts to 20 win over Bridgend.
Neath are battling for the runners up position but will be looking to deny the Arms Park side an unique league and cup double in the competitions inaugural final.
Ryan Williams starts at scrum half partnering Dylan Pugh, who contributed so effectively to the semi-final success away to Pontypridd. Wing Andrew Jones returns while the pack remains unchanged.
Cardiff show just two changes from the side which defeated Llanelli in the last round with Darren Ryan selected at centre and lock Tait returning to the side after his recent run in the senior side.
Neath U'21s: P.Thomas, R.Carter, M.Jones, P.Smiriglia, A.Jones, D.Pugh, R.Williams, P.James, A.Matthews (capt), A.Jones, G.Evans, L.Bassett, S.Peters, D.Evans, S.Phillips
Cardiff U'21s: C.Anderson, E.Jones, O.Ashman, D.Ryan, G.Williams, N.Macleod, C.Miller (capt), J.Yapp, K.Jarma, D.Evans, L.Tait, C.Stamatakis, J.Malpas, M.Leach, M.Leaman
Dodgy tattoos, carthorses, Avatar and soft chins are revealed by Wales Sevens players Tom Williams and Sam Cross as they profile the Wales Sevens squad taking part in Hong Kong this weekend in the latest round of the HSBC Sevens World Series.
The youngest member of the Wales Women's squad, Keira Bevan, is hoping to repay the faith shown in her when she starts her first Six Nations game against Italy tomorrow evening in the final round of the championship.
Sevens head coach Gareth Williams is a happy man after drafting in full internationals Rhodri Williams and Adam Warren for the next two rounds of the world series in Hong Kong and Japan, as WRU TV's Graeme Gillespie discovers.