Australia's Rocky Elsom and Matt Giteau have accepted an invitation to play for the Barbarians against rugby world champions South Africa at Twickenham in December.
The two Wallabies played in the invitational club's win over the world champion Springboks in 2007 and against New Zealand last year.
The December match will also feature the long-awaited return of controversial Wales centre Gavin Henson.
The Ospreys midfielder has not played since March 2009 after suffering an ankle injury and then taking unpaid leave.
Henson has also been linked with a move to several English Premiership clubs, but all have denied making an approach.
The talented Henson, capped 31 times for Wales, has also made clear his desire to play for his country at next year's World Cup in New Zealand but he has a lot to achieve before his dream will come true.