The Ospreys will be looking to bounce back from their 17-0 loss to Gloucester in the EDF Energy Cup by getting back on track in the Magners League at Ulster, but will be without a number of internationals.
The region were hit by a double blow this week, with Wales pair Gavin Henson and Jonathan Thomas being ruled out for the rest of the season.
Flanker Thomas has suffered a recurrence of a long-term groin problem, and has been advised to take three months recovery, while centre Henson was withdrawn during Saturday's semi-final against Gloucester and will out until early May.
Ian Gough was also taken off against Gloucester, suffering a haematoma in his hip, and will miss the Ulster clash but hopes to be fit for next weekend's match with Munster in the Heineken Cup quarter-final.
Lee Byrne remains on the sidelines as he recovers from damaged ligaments suffered in Wales's Six Nations finale against Ireland, while two other Welsh internationals in Shane Williams and captain Ryan Jones will not travel with the side to Northern Ireland.
Host Ulster had found form during the Six Nations break, having won both of their matches in this period, although like the Ospreys lost to Leinster in their last Magners League game.
Coach Matt Williams will be without Stephen Ferris, Bryn Cunningham and Paul Steinmetz but can call upon NiallO'Connor and Mark McCrea, who have been added to the squad for Friday night. And Williams is taking nothing for granted despite the Welsh region's weakened state.
"The Ospreys are a fantastic team and physically massive. No-one expects us to win so there isn't much pressure on us," said Williams.
"They are individually the best team in the competition with a big squad of very high quality players so it could be our toughest game at Ravenhill this season."
Forwards: Brendon Botha, Tom Court, Bryan Young, Ed O'Donoghue, Matt McCullough, Carlo del Fava, Chris Henry, Nigel Brady, David Pollock, Rory Best, Ryan Caldwell, Robbie Diack.
Backs: Simon Danielli, Andrew Trimble, Darren Cave, Cillian Willis, Niall O'Connor, Clinton Schifcofske, Ian Whitten, Isaac Boss, Ian Humphreys, Timoci Nagusa, Mark McCrea, Paddy Wallace.
Ospreys : Gareth Owen; David Bishop, Jonathan Spratt, Andrew Bishop, Jonny Vaughton; James Hook, Mike Phillips; Paul James (capt), Huw Bennett, Cai Griffiths, Alun Wyn Jones, Andy Lloyd, Tom Smith, Steve Tandy, Filo Tiatia.
Replacements: Richard Hibbard, Ryan Bevington, Filipo Levi, Marty Holah, Jamie Nutbrown, Dan Biggar, Sonny Parker.
Beating Merthyr has boosted Carmarthen Quins hopes of reaching a top eight spot in the Principality Premiership. Quins captain Haydn Pugh is delighted with his team's progress and is determined that everyone from the Under 6s through to the senior team, enjoys the ride.
When the Wales squad were asked to nominate individuals who played a big part in their early playing days, Wales and Dragons full back and wing Hallam Amos thought of his former Monmouth School rugby coach John Bevan.
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