New Cardiff coach Dai Young and his men return to their home ground keen to turn around the poor start they have made season. Defeats to Glasgow and Connacht, followed by a narrow win over Scottish minnows Borders, mean Cardiff are struggling to make the Celtic League quarter finals.
Defending champions Leinster travel to Cardiff without their Ireland internationals - including brilliant centre Brian O'Driscoll - and hard questions will be asked of Young and his men if they don't leave the Arms Park with a victory.
Young has rushed Cardiff's two new arrivals from Africa into the side. South African fullback Donavan van Vuuren replaces Rhys Williams and Namibian lock Heino Senekal steps in for the injured John Tait.
"They've both worked hard in training this week and we are taking the first opportunity to give them a game," Young said.
"I am also mindful that players such as Rhys Williams have been ever-present so far this season and need a break to recharge their batteries."
At Stradey Park, Welsh bookmakers Jack Brown have given Ebbw Vale a 24-point start against Llanelli, and they'll need them.
Llanelli have had a mixed start to the Celtic League with losses to Munster and Neath, but they should beat the rest of Pool A without too much trouble.
The Scarlets are missing No 8 Scott Quinnell (nose operation), but welcome back captain Leigh Davies from injury.
Llanelli coach Gareth Jenkins says his side have to win their next three games to reach the Celtic League quarter-finals.
"We have to win against Ebbw Vale, then Swansea at home and travel for a tough contest in Ulster," he said. "It's all about qualification and we need a result in all three to get back into contention.
"Leigh will provide a massive boost in midfield and I've seen enough positive things over the last few weeks to be confident things are coming together."
Davies replaces New Zealander Matt Cardey in the centre, with Gareth Bowen coming in at fly-half for Wales international Stephen Jones. Prop Iestyn Thomas is also rested, with Phil Jones stepping in.
At Virginia Park, Todd Blackadder's Edinburgh team should hold too many aces for Caerphilly. Edinburgh are enjoying a fruitful tournament and will be looking for a big win to cement their place in the top four of Pool A.
In contrast, Caerphilly are winless in a season and a half of Celtic League rugby, and last week's poor effort against a 14-man Ebbw Vale side indicates that's not about to change.
LLANELLI v EBBW VALE (at Stradey Park, 2.30pm).
Llanelli: G Evans, M Jones, M Watkins, L Davies (capt), S Finau; G Bowen, D Peel; P John, M Thomas, M Madden, V Cooper, L Gross, D Jones, I Boobyer, D Hodges. Replacements: I Thomas, R McBryde, C Wyatt, G Williams, M Phillips, S Jones, M Cardey.
Ebbw Vale: (not yet available)
Out - Llanelli: L Davies (knee), C Wyatt (shoulder), N Boobyer (stress fracture of foot).
Ebbw Vale: C Billen (back), D Penisini (knee), J Evans (cut head).
Previous Celtic League meeting: Llanelli 46 Ebbw Vale 16 18/8/01). Welsh/Scottish League wins: Llanelli 10-4 with two dra\wn.
Last season: Llanelli won 46-16 home and 16-3 away in the league and by 34-17 in a Principality Cup semi-final at the Millennium Stadium.
Previous Celtic League meeting: Llanelli 46 Ebbw Vale 16.
Form guide: Ebbw Vale have only won once at Stradey in a league match - 15-12 in 1997/98. In all meetings Llanelli lead 59-28 with nine drawn and one abandoned.
CAERPHILLY v EDINBURGH RUGBY (at Virginia Park, 2.30pm).
Caerphilly: O Ashman; G Lewis, S Cox, J Murphy, R Howells; L Richards, S Tuipulotu; L Manning, C Ferris (capt), R Skuse, M Workman, N Rouse, J El-Abd, A Williams, G Jones. Replacements: A Chilten, F McLoughlin, R Boobyer, F Vunipola, D Sweet, N Watkins, R Bilton.
Edinburgh: B Laney; D Lee, C Joiner, A Dickson, C Paterson; D Hodge, M Blair; A Jacobsen, D Hall, C Smith, N Hines, S Murray, T Blackadder (capt), S Taylor, M Leslie. Replacements: A Kelly, J Brannigan, A Kellock, A Dall, M McMillan, T Philip, S Webster.
Out - Caerphilly: T Taufahema (ankle), S Jarman.
Previous Celtic League meeting: Edinburgh 27 Caerphilly 20 (7/9/01). Welsh/Scottish League wins: Edinburgh 6-0, three at home and three away.
Last season: Edinburgh 27 Caerphilly 20; Caerphilly 21 Edinburgh 35.
Form guide: Caerphilly have beaten Glasgow at home, but never defeated Edinburgh.
CARDIFF v LEINSTER LIONS (at the Arms Park, 5.30pm).
Cardiff: D van Vuuren; N Walne, J Robinson, P Muller, A Sullivan; I Harris, R Powell; T Payne, G Woods, G Powell, H Senekal, A Jones, R Appleyard, D Baugh, M Williams (capt). Replacements: K Fourie, A Lewis, L Tait, D McShane, R Smith, N Robinson, R Williams.
Leinster: C Warner; K Lewis, S Horgan, D Quinlan, G D'Arcy; A Dunne, B O'Meara; E Byrne, P Smyth (capt), N Treston, B Gissing, A Kearney, E Miller/A McCullen, D Dillon, L Toland. Replacements: P Coyle, G Hickie, A McCullen/S Jennings, N Breslin, B Willis, M Leek, Journalist McWeeney.
Referee: Iain Ramage (Scotland).
Out - Cardiff: E Lewis (sternum), R Sowden-Taylor (knee ligaments), J Brownrigg (shoulder), D Dewdney (back spasm), S John (neck), J Tait (back), A Lewis (hip), P Rogers (back), C Morgan (rested).
Leinster: N Spooner, V Costello, P McKenna, A Magno.
Previous meeting: Cardiff won away by 23-14 in a semi-final of the 1995/96 European Cup.
Form guide: Cardiff hope to make amends for losing at home to Glasgow, while Leinster come as reigning champions.
Sam Cross and Luke Treharne have been named as co-captains of the Wales Sevens side as head coach Gareth Williams names his 12-man squad to play in the first leg of the HSBC World Series in Dubai next weekend.
Bedwas head coach Steve Law and players Nicky Griffiths and Alun Rees extol the virtues of the close knit club as they prepare to host third place RGC 1404 - who are one place head of them on the Principality Premiership points table - on Saturday.
Many of the Wales squad have said Diolch (thank you) to someone who played an important part in their early playing days by nominating them to be invited to the Wales v South Africa match. One person, Gowerton Comprehensive geography teacher Mr Dean Mason was nominated by two of his former pupils, Dan Biggar and Sam Davies.
The second WRU disability rugby pilot has been delivered, this time in Caerphilly schools, culminating in a festival at the Caerphilly Centre of Sporting Excellence, Ystrad Mynach tomorrow. Plans are in place to set up a Disability Rugby Club in Newbridge to provide long-term playing opportunities.
WRU TV: Hear from inside the Wales camp as Neil Jenkins discusses this weekend's clash with South Africa and how the squad are looking to put in a strong performance to round of the 2016 Under Armour Series