And Warren Gatland and co now know who they'll be up against after the Baa-Baas added a further six players to their summer squad.
Barbarians coach Dai young - a Lion on the last two visits to Australia in 1989 and 2001 - has added a South African, Fijian, Italian, Australian, American and an Englishman to his already cosmopolitan party.
Saracens and Springbok hooker Schalk Brits joins Exeter's ex-Wallaby lock Dean Mumm, Wasps youngster Elliot Daly and Northampton's USA forward Samu Manoa in adding an extra Aviva Premiership presence, while Montpellier's Fijian wing Timoci Nagusa is also included and veteran Italian prop Andrea lo Cicero gets a well-deserved swansong following his international retirement.
Brits missed out on playing against the Lions for the Boks four years ago, while Mumm left Australia last summer after discovering he wasn't in the running for a Qantas Wallabies spot against Britain and Ireland's elite.
Daly is another with a point to prove having missed out on selection for England's tour of Argentina - the Baa-Baas face Stuart Lancaster's side at Twickenham a week before playing the Lions.
Manoa has made a huge impact this season with the Saints and will be in action alongside 2013 Lion Dylan Hartley and against Dan Cole, Tom Croft, Geoff Parling, Manu Tuilagi, Ben Youngs and Tom Youngs in the Aviva Premiership Final in a week-and-a-half's time. The 28-year-old will therefore miss the match against England but will be free to feature at the Hong Kong Stadium.
"We are very pleased with the final composition and strength of the squad," said Barbarians tour manager Derek Quinnell.
"Obviously because of play-off finals in Ireland and England on May 25 a handful of players will not be available for the first match against England but we have covered that by inviting 28 players.
"We also believe there is a healthy balance between proven Test experience and promising young talent who will benefit enormously from the experience."
The Baa-Baas had previously announced that a whole host of international talent would be joining their ranks, with the likes of Italy captain Sergio Parisse, French veteran Imanol Harinordoquy and former All Blacks duo Nick Evans and Joe Rokocoko included.
Ex-Lions trio James Hook, Dwayne Peel and Matthew Rees are also involved, while Paul James and Scott Hamilton will be looking to bounce back from their own disappointment after missing out on Lions selection despite strong seasons.
Backs: Jared Payne (Ulster), Elliot Daly (London Wasps), Rowan Varty (DeA Tigers & Hong Kong), Takudzwa Ngwenya (Bairritz Olympique & USA), Joe Rokocoko (Bayonne & New Zealand), Timoci Nagusa (Montpellier and Fiji), 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), B J Botha (Munster & South Africa), Paul James (Bath Rugby & Wales), Martin Castrogiovanni (Leicester & Italy), Andrea lo Cicero (Racing Metro and Italy), Schalk Brits (Saracens and South Africa), Matthew Rees (Scarlets & Wales), Leonardo Ghiraldini (Benetton Treviso & Italy), Dean Mumm (Exeter Chiefs and Australia), Marco Wentzel (London Wasps & South Africa), Jim Hamilton (Gloucester Rugby & Scotland), Samu Manoa (Northampton Saints and USA), Francois Louw (Bath Rugby & South Africa), Sam Jones (London Wasps), Alessandro Zanni (Benetton Treviso & Italy), Sergio Parisse (Stade Francais & Italy), Imanol Harinordoquy (Biarritz Olympique & France)
Coach: David Young (London Wasps)
Player / assistant coach:Mike Tindall (Gloucester Rugby & England)