The invitational XV have already received acceptances from Wallaby stars Rocky Elsom and Matt Giteau and former Lions tourist Gavin Henson.
Mike Phillips, one of the standout performers on the Lions' 2009 tour of South Africa, has also been invited to wear the black and white of the Barbarians.
Phillips is likely to go head-to-head with Elsom and Giteau when the Lions travel Down Under in 2013, while Henson is still young enough to take part in a second Lions tour if his rugby comeback proves successful.
The 28-year-old hasn't played for 18 months but has made it clear he intends to return to the game in the near future.
The Grand Slam winning centre has asked to be released from his Ospreys contract and is hoping to join a London-based club for at least the remainder of the season.
"Obviously our invitation to Gavin will attract a lot of attention," said Barbarians' contracts manager and former Lion Mike Burton.
"He has other commitments outside rugby and he is conscious of the need for match fitness in order to do himself and the club justice."
Although Henson has accepted the invitation, his appearance may depend on his progress in the BBC reality TV show Strictly Come Dancing.
The remainder of the Barbarians squad will be announced in the coming weeks, although it has already been confirmed that Italy's South African coach Nick Mallett and ex-Ulster and Northampton boss Alan Solomons will again take charge of the side.