Ireland fly-half Ian Madigan and retiring prop Mike Ross have been included in a 27-man squad for the Barbarians' matches against England and Ulster.
Madigan has plied his trade in France with Bordeaux this season, while Ross recently played his last game for Leinster.
Head coach Vern Cotter will select from a squad containing 1,018 caps for the games at Twickenham on May 28 and Kingspan Stadium on June 1.
Scotland prop WP Nel, Saracens hooker Schalk Brits, Argentina wing Horacio Agulla and Wales hooker Richard Hibbard are also among those chosen.
Backs: H Agulla (Castres & Argentina), A Ashley-Cooper (Bordeaux Begles & Australia), Y David (Toulouse and France), K Fotuali'i (Bath Rugby & Samoa), R Freuan (Bath Rugby), R Kockott (Castres & France), I Madigan (Bordeaux Begles & Ireland), T Nagusa (Montpellier & Fiji), W Nayacalavu (Stade Francais & Fiji), R Pienaar (Ulster & South Africa), D Smith (Castres), F Steyn (Montpellier & South Africa).
Forwards: P Albacete (Toulouse & Argentina), S Armitage (Pau & England), S Brits (Saracens & South Africa), T Dusautoir (Toulouse & France), C Flynn (Star RFC & New Zealand), B Franks (London Irish & New Zealand), G Galan (Toulouse), R Hibbard (Gloucester & Wales), F Isa (Lyon & Argentina), C Johnston (Toulouse & Samoa), M Nariashvili (Montpellier & Georgia), WP Nel (Edinburgh & Scotland), M Ross (Leinster & Ireland), J Tekori (Toulouse & Samoa), J Thrush (Gloucester & New Zealand).