The man charged with leading The Lions to a first series triumph in 16 years says combinations in the front row, back row and midfield were all discussed in length before the side was announced to the press and public this afternoon.
"The make up of the loose forwards was one (of the tight calls), front row was a big discussion as well, and that combination in the midfield," said Gatland, who picked Alex Corbisiero ahead of Mako Vunipola and Tom Youngs instead of Richard Hibbard, while Jonathan Davies starts at inside centre and Tom Croft and Jamie Heaslip partner skipper Sam Warburton at blindside flanker and No8.
"A lot of players were rewarded for their performance last Saturday against the Waratahs. That was an extremely positive performance and a lot of the side is made up from that team.
"Mako's pretty unlucky. We've looked at the weather conditions and potentially there is a threat of showers. I've no doubt that Robbie Deans has looked at Mako technically at scrum time so him coming off the bench will give us a huge amount of impetus. We think that will be a big strength. Technically, Alex is probably a little bit sounder, and we feel we've potentially got a little bit of an edge there.
"I don't think Jonathan Davies at 105kg is a small midfielder. Just because he's not as tall as the other two (Roberts and Tuilagi), I don't see him lacking a physical element at all. What it does gives us is a few more subtleties, and we've got some pace and firepower out wide, too.
"George North had to pass a fitness test. He came through a good workout yesterday and we had to make sure there was no reaction from that. He's confident and positive."