Bath-based Springbok Francois Louw will play for the Barbarians against the British and Irish Lions.
Jaque Fourie was also invited but has withdrawn.
Former Springboks BJ Botha and Marco Wentzel are also included in a squad that is a mixture of the outstanding and the ordinary.
The Barbarians also play England at Twickenham on May 26.
Backs: Jared Payne (Ulster), Rowan Varty (DeA Tigers, Hong Kong), Takudzwa Ngwenya (Biarritz Olympique, USA), Joe Rokocoko (Bayonne, New Zealand), James Hook (Perpignan, Wales), Nick Evans (Harlequins, New Zealand), Kahn Fotuali’i (Ospreys, Samoa), Dwayne Peel (Sale Sharks, Wales), Dimitri Yachvili (Biarritz Olympique, France).
Forwards: Duncan Jones (Ospreys, Wales), BJ Botha (Munster, South Africa), Paul James (Bath, Wales), Martin Castrogiovanni (Leicester, Italy), Matthew Rees (Scarlets, Wales), Leonardo Ghiraldini (Benetton Treviso, Italy), Marco Wentzel (London Wasps, South Africa), Jim Hamilton (Gloucester, Scotland), Francois Louw (Bath, South Africa), Sam Jones (London Wasps), Alessandro Zanni (Benetton Treviso, Italy), Sergio Parisse (Stade Français, Italy), Imanol Harinordoquy (Biarritz Olympique, France).