For months, Gatland and his sidekicks will have trimmed their ideas about how to get the best out of their playing group to confront the All Blacks while also interacting with their host audiences.
The Lions know how they want to play in New Zealand and they've had a couple of camps to lay down those concepts and now it's a case of finding the right players to fit into that jigsaw. Losing Billy Vunipola to injury is a significant blow but Toby Faletau and others are talented options and selection is where the Lions' nerve will be tested.
They will have ideas about players who should be concrete test choices -George North, Owen Farrell, Sam Warburton, Maro Itoje, Tadhg Furlong - but they have to be confirmed. National partnerships such as Conor Murray and Johnny Sexton should be unpicked and tried with new links while using Farrell and Itoje in different positions may accrue greater team rewards.
The enemy is time. Work on the training track is the plinth for any success but match-play is the platform where production and decisions under pressure are the best gauge of any player's calibre.
Six games before the first test at Eden Park is not a stack of chances to juggle ideas, especially if conditions and inevitable injury toll bite into the planning so the Lions have to be creative and inventive about their practices and keeping their squad on a selection edge.
They have a high-quality professional squad who will rapidly absorb a team approach and should deliver sustained impact from their forwards, a tight team defensive pattern, kick goals and have the necessary sting with their backline attack. These Lions have the motivation of unseating the No1 side in the world.
The All Blacks have injury issues to key players, a test with Samoa to survive and national pressure surging towards the opening June 24 test at Eden Park. Success at the America's Cup or the Champions Trophy will intensify the country's expectation.