POOL A - ULSTER v MUNSTER (at Ravenhill, Belfast, 7.35pm).
Munster, the only unbeaten side in Pool A travel to Belfast hoping to repeat last season's 15 - 9 Celtic League semi-final victory over the 1999 Heineken Cup champions.
Both sides are missing their Irish international players who are preparing for Saturday's World Cup qualifier against Georgia in Dublin.
Ulster will be captained by Irish international lock Jeremy Davidson in the absence of the injured Andy Ward, and after a fine performance against Neath last weekend, Adam Larkin continues at fly half.
Mick Galway skippers Munster due to an injury to Jim Williams. Williams has a damaged knee, and coach Alan Gaffney is wary of risking the influential flanker.
"Jim's injury is not too serious, a little swelling on the knee, but at this stage of the season we're not prepared to take chances," said Gaffney.
"It is never easy to get anything out of Ravenhill and we can expect a capacity crowd to get right behind Ulster. It's a game they know they must win. So all in all, I'd say we're right up against it."
Ulster: B Cunningham; J Topping, R Constable, J Bell, T Howe; A Larklin, N Doak; J Fitzpatrick, M Sexton, R Kempson, M Blair, J Davidson (capt), W Brosnihan, T McWhirter, N McMillan. Replacements: S Best, P Shields, P Johns, N Best, K Campbell, S Stewart, S Young.
Munster: J Staunton; D Crotty, M Mullins, J Holland, M Lawlor; K Keane, M Prendergast; M Horan, F Sheahan, R Laffan, M Galwey (capt), M O'Driscoll, D O'Callaghan, E Halvey, D Leamy. Replacements: J Blaney/J Fogarty, S Kerr, T Hogan, C McMahon, D Malone, C Mahony, C Huppert.
Referee: P Adams (Wales).
Out - Ulster: A Ward (ankle), J Williams (knee), S Coulter.
Munster: D Wallace, A Horgan, P O'Connell, M Cahill.
POOL A - NEATH v EBBW VALE (at the Gnoll, 6.45pm).
Despite falling to Ulster last weekend, Neath are in a rich vein of form, and with three wins in this years Celtic League, the Welsh All Blacks will start this match as hot favourites.
But Neath coach Lyn Jones is keeping his feet firmly on the ground
"Over the last four years we have had some great high scoring matches against them, and the moment you take a win for granted you will lose."
Neath won both meetings in the Welsh/Scottish League, but Vale were victorious in the Principality Cup last season. The Steelmen have only won twice in Welsh League games at the Gnoll, 16-15 in 1996/97 and 22-20 in 1998/99.
Ebbw Vale have recorded just one victory in the Celtic League this season, against Caerphilly.
Peter Sidoli, younger brother of Pontypridd lock Robert, is impressing after sitting most of last season out with injury.
Coach Mike Ruddock had words of support for the young forward. "Peter [Sidoli] made things happen on Saturday," he said
Ruddock has included flanker Paul Williams at openside flanker with Tyron Morris suffering from a neck injury. Willaims recent memories of the Gnoll include a sending off last season, so he will be keen to make up for that this weekend.
Neath: (from) Backs - G Morris, J Story, D Tieuti, A Bateman, S Williams, L Jarvis, S Marsden, S Connor, A Moore, P Horgan. Forwards - D Jones, A Jones, A Millward, S Jones, B Williams, G Llewellyn (capt), A Newman, H Jenkins, S Martin, A Mocelutu, S Tandy, N Bonner-Evans.
Ebbw Vale: R Davies; N Wakely, M Ridley, E Binham, R Shorney; M Meenan, B Shelbourne; P Jones, J Evans, A Black (capt), P Sidoli, N Edwards, K Tuipulotu, W Thomas, P Williams, Replacements: C Gay, K Crawford, O Booyse, R Williams, A Bevan, S Mitchell, A Takarangi.
Referee: G Davis (Scotland).
Out - Neath: B Sinkinson (knee), J Leyshon (shoulder), A Matthews (knee).Ebbw Vale: C Billen (back), D Penisini (knee), T Morris (neck), P Matthews (ankle)
Previous meetings: In Welsh league matches Neath lead 9-7 on wins overall
and by 6-2 at home.Last season: Neath won 45-6 away and 50-8 home in league matches, but Ebbw Vale won 20-10 at home in the Principality Cup Round Seven.
Form guide: Ebbw Vale's only league wins at the Gnoll were by 16-15 in
1996/97 and 22-20 in 1998/99.
POOL A - EDINBURGH RUGBY v LLANELLI (at Meadowbank, 7.30pm).
Llanelli take their strongest available side to Scotland hoping to break their Meadowbank duck. The Scarlets have lost all three previous games Edinburgh's home stadium.
Scarlets coach Gareth Jenkins makes three changes from the side that beat Ebbw Vale 37-25 last weekend. Wales trio Stephen Jones, Iestyn Thomas and Robin McBryde come in for Gareth Bowen, Phil John and Marcus Thomas at fly-half, prop and hooker respectively.
Simon and Guy Easterby are unavailable for selection as they are included in Ireland's squad for the World Cup qualifier against Georgia in Dublin.
Jenkins says his Scarlets have to win all their remaining matches, and with Edinburgh pushing for top spot in Pool A, this will be no easy task.
Jenkins knows the Scarlets must raise their game in order to win.
"We are going up a class when we play these teams (Irish and Scottish) but that brings the best out of Llanelli."
Edinburgh: (not yet available)
Llanelli: G Evans; M Jones, M Watkins, L Davies, S Finau; S Jones, D Peel; I Thomas, M.Thomas, M Madden, V Cooper, L Gross, D Jones, D Hodges, I Boobyer. Replacements: J Davies, M Thomas, C Wyatt, L Cudmore, M Phillips, G Bowen, M Cardey.
Referee: S McDowell (Ireland).
Out - Edinburgh: M di Rollo (knee).
Llanelli: N Boobyer (foot fracture); S Easterby & G Easterby (on Ireland duty), S Quinnell (nose), D Williams (knee).
Welsh/Scottish League wins: Three each with neither side winning an away
Last season: Llanelli 42 Edinburgh 17; Edinburgh 40 Llanelli 8.
POOL B - BORDERS v LEINSTER LIONS (at Netherdale, 7.30pm).
Celtic League champions Leinster are desperate for a victory to turn their campaign around.
A defeat to Borders would surely end all hope of quarter-final qualification. The Lions beat the Scottish Borders in the 1996/97 Heineken Cup 34-25, and a repeat performance will take the pressure off coach Matt Williams, who has come under increasing criticism from a Leinster public used to success.
The Borders will be without wings Shaun Longstaff (groin) and Cammie Murray (shoulder), and are desperate for a change of luck.
They have lost three matches by a combined total of five points, including last weekend's heartbreaking one point loss to Pontypridd.
Borders: T Vili; N Walker, K Utterson, J Stuart, C Moir; G Townsend, G Armstrong (capt); P Thomson, S Scott, B Douglas, D Weir, R Metcalfe, C Feather, S Sititi, M Taylor. Replacements: S Paterson, C Laidlaw, I Fairley, A Rennick, C Stewart, C Dunlea, S Gunn.
Leinster: C Warner; J McWeeney, K Lewis, S Horgan, G D'Arcy; A Dunne, B O'Meara; E Byrne, P Smyth (capt), N Treston, B Gissing, B Kearney, D Dillon, V Costello, L Toland. Replacements: P Coyle, G Hickie, A McCullen, S Jennings, S Keogh, M Leek/G Browne, D Quinlan.
Referee: H Watkins (Wales).
Out - Borders: S Longstaff (Groin), C Murray (shoulder), G Morton (shoulder),
G Graham (calf), S Cranston (ankle).
Leinster: N Spooner, P McKenna, A Magno, E Miller, B Willis, B O'Riordan.
Previous meetings: In the 1996/97 European Cup, Leinster won away 34-25.
All roads lead to Cardiff on Sunday for the SSE SWALEC Finals Day at the Millennium Stadium. Cambrian Welfare tackle Ystradgynlais in the Bowl final, Ystrad Rhondda play Newcastle Emlyn in the Plate final while defending champions Pontypridd face Bridgend in the Cup final.
WRU Chief Executive Roger Lewis, Deputy Minister for Culture, Sport and Tourism Ken Skates and WRU Chairman Gareth Davies earlier this week launched a new competition in conjunction with the WRU unveiling its archive room.
Welsh players and management joined Deputy Minister for Sport Ken Skates at the Pierhead Building, Cardiff Bay earlier this week to reveal the Union's pioneering school-club hub initiative has been so successful the project will now almost double the scale of the original project.
The Scarlets, Newport Gwent Dragons, Cardiff Blues and the Ospreys look ahead to Judgement Day III which sees the Blues take on the Ospreys (2.30) and the Dragons tackle the Scarlets (4.45pm) at the Millennium Stadium tomorrow afternoon.
Ystradgynlais and Ynysddu played out a titanic struggle at Taffs Well in the SSE SWALEC Bowl semi-final. At the end of the game neither team could be separated after a 15-15 stalemate but Ystradgynlais go through on try count.
Blues strike first in JD III battle - Newport Gwent Dragons lock Andrew Coombs, WRU referee Dylan Llyr Jones and Cardiff Blues hooker Matthew Rees decide dressing room allocations for Judgement Day III
Wales Under 18 captain Calum Haggett has received a conditional offer to read Biomedical Science at St Anne's College, Oxford. WRU chairman Gareth Davies went to meet Calum and Coleg y Cymoedd Principal Judith Evans to wish him luck in his exams and pass on some of his personal experience.
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.