Gatland admitted his Test side would need to be more disciplined against the Crusaders, who are undefeated in Super Rugby in 2017.
The British and Irish Lions team respond to their Maori welcome with a Welsh song as they arrive at Auckland International Airport.
Coach Tana Umaga said they were keen to unveil the new haka before Wednesday's match against the Lions kicked off in front of what is expected to be a sell-out 45,000 crowd.
Crusaders coach Scott Robertson predicted a "fantastic clash".
West then converted to give the hosts the win in Auckland. Loose forward Ross Moriarty has a back strain but was recovering well.
Leigh Halfpenny's third penalty had edged the Lions back into a one-point lead with 10 minutes to play, Sonny Bill Williams' break was finished off by West to snatch victory from the Lions' grasp. The speed of the game is slightly quicker - some of us haven't played for a couple of weeks - but that's no excuse.
If Farrell does become the favourite to start at fly-half it opens up the options for Gatland in the midfield.
"The aim was always to start everyone in the first three matches and this selection ensures we achieve this", Gatland said. "If we have to go to set-piece, we will".
"I've got to concentrate on me to make sure we can get the result on Saturday", said Davies. He brings that experience. "We haven't spoken about a test combination yet".
"Players are going to get one or two chances to make an impact before we start even thinking about any kind of Test line-ups". Rob Howley talked of "chaos" ahead of the game but the only confusion was in the Lions backline, which again failed to spark.
"Sonny Bill's a monster, isn't he?" he said. Big, well-drilled forwards won't be enough, that much is clear after a rotten performance against semi-professionals in Whangarei and a defeat to the Blues at Eden Park. Good work at the ruck, scrum, and the majority of lineouts provided quality ball for the backs.
"And this is the kind of victory that can stay with them for some time".
The young playmaker has helped Saracens to European Champions Cup glory and guided England to the Six Nations title in each of the last two years. West added a penalty early in the second period.
Farrell appreciated the difficulty of the task at Christchurch's AMI Stadium.
Alun Wyn Jones will lead the Lions against the Crusaders.
Adding to the Crusaders' depth is eight-Test flanker Matt Todd, who is on standby as injury cover for the Lions series, and winger Seta Tamanivalu, who missed the worldwide cut this year.
The Lions will be desperate to atone for Wednesday's 22-16 loss to the Blues in Christchurch this weekend, but will face down a Crusaders outfit boasting 14 wins from 14 Super Rugby encounters. Replacements: K Owens, J McGrath, D Cole, M Itoje, CJ Stander, R Webb, J Sexton, A Watson.