Leonard is set to play against his former team-mates at Twickenham

Club commitments could affect their participation in the tour, but the pair are due to face their former England team-mates at Twickenham on 30 May.

Leonard will miss the Scotland game on Saturday to play for Harlequins in the Parker Pen Challenge Cup final.

Back might be needed for Leicester's Zurich Wildcard final on 29 May.

Australian Matt Burke, who is without a club, has also been named in a 36-man squad boasting 1,317 international caps.

Ireland captain Brian O'Driscoll is joined in the backs by his fellow Triple Crown winners Geordan Murphy, Shane Horgan and David Humphreys.

Former New Zealand star Christian Cullen is also included alongside Kiwi threequarters Bruce Reihana and Mark Robinson.

Back will fight it out with France's Olivier Magne and Italian back rower Aaron Persico for the number seven jersey, while Taine Randell and Bobby Skinstad will compete for the number eight duties.

New Zealanders Josh Blackie and Matt Sexton and London Irish winger Paul Sackey are the uncapped players.

It is Barbarians tradition to include one non-international in every starting line-up.

Former Australia coach Bob Dwyer will again coach the side.

The tour opens at Murrayfield on Saturday, moving to Ashton Gate in Bristol for a clash with Wales on 26 May before concluding against England at Twickenham.

Barbarians squad: C Cullen (NZ), G Murphy* (Irl), B Reihana (NZ), S Terblanche (SA), B Paulse (SA), P Sackey (Eng), V Delasau (Fij), S Horgan (Irl), B O'Driscoll (Irl), M Burke (Aus), N Grey (Aus), T Castaignede (Fra), D Humphries (Irl), N De Kock (SA), M Robinson (Nzl), J Leonard* (Eng), O Le Roux (SA), C Visagie (SA), G Feek (Nzl), R Bands (SA), A Oliver (Nzl), M Sexton (Nzl), M Andrews (SA), M O'Kelly (Irl), M Connors (Aus), B Mika (Nzl), O Finegan (Aus), E Miller (Irl), A Vos* (SA), J Blackie (Nzl), A Persico (Ita), N Back* (Eng), O Magne (Fra), T Randell (Nzl), B Skinstad (Rsa).

Coach: Bob Dwyer (Aus)