England's 2003 RBS 6 Nations and 2003 World Cup heroes Jason Robinson, Lawrence Dallaglio and Steve Thompson have been invited to play for the northern hemisphere team against the southern hemisphere in the Tsunami appeal match at Twickenham on March 5.
Scotland have confirmed Gordon Bulloch, Chris Cusiter and Simon Taylor will be available to play in the fund-raiser.
Australia trio George Gregan, Phil Waugh and Chris Latham plus All Blacks Tana Umaga, Carl Heoft, Andrew Mehrtens and Jerome Kaino are expected to feature in a world-class south team.
Morne du Plessis, manager of the southern hemisphere side, said: "We accept that this is a significant sacrifice made by their Super 12 and club teams, and the players themselves - but such is the very nature of this event."
The full squads are expected to be announced next week.
Wales' acting head coach Rob Howley has given Sam Davies and Rory Thornton a boost ahead of the RBS 6 Nations by naming the uncapped Ospreys duo in his largely experienced squad for the Autumn Internationals.