One of five Welsh players in Sir Clive Woodward's Northern 22 for the fund raising fixture, Yapp will pack down against South African giant Kobus Visagie. Sale's Andrew Titterell and Worcester's Chris Horsman, who is hoping to qualify for Wales in the summer, complete the North front row.
Dragons scrum half Gareth Cooper is given the chance to shine in front of Lions coach Woodward having been forced to act as Dwayne Peel's understudy in the championship and he will form a half-back pairing with Ulster and Ireland legend David Humphreys.
Cooper couldn't have asked for a better chance to shine as he will oppose the world's most capped scrum half, Australian World Cup winner George Gregan, while New Zealand's leading points scorer Andrew Mehrten's will join him at half-back in a unit that boasts 176 caps.
Wales also provide three replacements to a North XV that will now be captained by Lawrence Dallaglio following the withdrawal of Ireland's Brian O'Driscoll. Jonathan Thomas, Ceri Sweeney and Mike
Phillips are all likely to get some game time in a match that is set to raise hundreds of thousands of pounds for the IRB's humanitarian partner, the United Nations' World Food Programme (WFP), to support their vital work in affected areas following the devastating Tsunami on Boxing Day.
There are no fewer than six present or former international captains in the two sides and the North XV's original choice as captain, Irish skipper Brian O'Driscoll who will be pitchside with the team but unable to take part.
"I have spoken to Brian and he is bitterly disappointed not to be playing. However, he has come over for the game to show his support from the guys. I am delighted that Lawrence is involved as captain. He is a proven, outstanding player and he is relishing the prospect of stepping up to the mark and taking on the role of captaincy for this unique match," said Woodward.
Tickets for the game are available at www.ticketmaster.co.uk or by calling +44 870 9020000.
South XV: Chris Latham (Aus); Brian Lima (Samoa), Jacques Fourie (SA), Tana Umaga (NZ), Sireli Bobo (Fiji); Andrew Mehrtens (NZ), George Gregan (Aus, captain); Carl Hoeft (NZ), John Smit (SA), Kobus Visagie (SA), Simon Maling (NZ), Victor Matfield (SA), Schalk Burger (SA), Phil Waugh (Aus), Toutai Kefu (Aus). Replacements: Ephraim Taukafa (Tonga), Eusebio Guinazu (Arg), Semo Sititi (Samoa), Opeta Palepoi (Samoa), Moses Raulini (Fiji), Tinus Delport (SA), AN Other.
North XV: Chris Paterson (Scot); Mirco Bergamasco (It), Ollie Smith (Eng), Damien Traille (Fra), Ben Cohen (Eng); David Humphreys (Ire), Gareth Cooper (Wal); John Yapp (Wal), Andy Titterrell (Eng), Chris Horsman (Worcester), Marco Bortolami (It), Donncha O'Callaghan (Ire), Lawrence Dallaglio (Eng, captain), Pat Sanderson (Eng), Simon Taylor (Scot). Replacements: Raphaël Ibanez (Fra), Cédric Soulette (Fra), Oliver Brouzet (Fra), Jonathan Thomas (Wal), Mike Phillips (Wal), Ceri Sweeney (Wal),
Mathew Tait (Eng).