But their proud unbeaten record is likely to face a much bigger challenge than ever before in the opening fixture on Australian soil when they face the first of five Super Rugby franchises. No longer will there be easy pickings from a newly assembled Western Australian XV
The Western Force will come into the game battle-hardened after 14 Super Rugby matches, buoyed form a win over the Highlanders in their last fixture and rested after a week off.
The great Nathan Sharpe may have finally hung up his boots, but new skipper Matt Hodgson has stepped into the breach and has led his side to an away win in Brisbane over the Queensland Reds and morale boosting home victories against New Zealand teams the Crusaders and Highlanders.
Head coach Michael Foley and his assistant Steve Meehan know all about northern hemisphere rugby having coached in the Aviva Premiership, but they will have to go into the game without fit-again No 8 Ben McCalman, who was called up into the Qantas Wallaby squad last weekend as injury cover for Scott Higginbotham.
The game will give Brian O'Driscoll the chance to open his playing account on his fourth Lions tour in the same city where he made his debut 12 years ago. He will lead a team that contains five newcomers in the starting XV and two more new Lions among the replacements.
O'Driscoll's will be one of four Irish backs in the Lions side and his midfield partnership with England's blockbusting Manu Tuilagi will be centre of attention for the Force defenders as well as the Lions coaches.
Having kicked-off their tour with an eight try win over the Barbarians the Lions know they will have to step up their efforts and cut out the early handling errors that saw them lose three or four scoring chances against the Baa-Baas.
Sean O'Brien will fill the No 7 jersey in the continued absence of tour captain Sam Warburton, who will be one of only three players still waiting for a game after the opening two matches. The others are Rob Kearney and Gethin Jenkins.
The Youngs brothers, Tom and Ben, are among the replacements and will become the 14th set of brothers to represent the Lions once scrum half Ben takes the field. The Ospreys provide the second row pairing in Alun Wyn Jones and Ian Evans and O'Brien will join Leinster team mate Jamie Heaslip in the back row.