That selection process effectively begins at Hong Kong Stadium on Saturday when 2009 Lions captain Paul O'Connell leads the tourists into action. Starting with the Barbarians, there are six games before Gatland's Test XV runs out against the Wallabies in Brisbane.
"What we've always said is that everyone will get a start in the first three games, and we will look at certain combinations, mixing and matching a little bit," said Gatland.
"The great thing at the moment is there is a huge amount of competition within the squad. I think a lot of players feel that if they play well and put their hand up they've got a chance of being selected.
"The guys who go out on Saturday get their first opportunity to set a mark and put some pressure on the other players in the squad.
"In terms of the Test side, probably not until after the first four games will we actually even start thinking about that. I think it is important that these players feel like they've got a chance to go out and impress.
"As coaches and management, we are not going around with any preconceived ideas about what we think the Test side should look like."
O'Connell will seal his comeback from serious injury by captaining the Lions this weekend. Only a few months ago, the 33-year-old Ireland lock did not expect to be part of what is now his third Lions mission.
But with tour skipper Sam Warburton resting a knee injury - Gatland described his absence from the Baa-baas encounter as "precautionary" - O'Connell takes over as leader against the Barbarians.
He will take charge of a team containing nine Welshmen - including the entire back row of Dan Lydiate, Justin Tipuric and Toby Faletau - three Scots and two English.
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