"These are players currently on international duty who we are looking forward to welcoming into the Tour party as we did with several players in 2013. I spoke to all the Home Union coaches prior to departure and explained our thinking and they were all supportive."
Gatland has selected Scottish and Welsh only because they are in location to make short-haul trips from Sydney and Auckland.
England, meanwhile, are on tour in Argentina and Ireland are in Japan.
The composition of three front-rows, one lock, one scrum-half and one fly-half will, in theory, allow Gatland to rest his entire 23-man Test squad against the Chiefs.
Despite Stuart Hogg's departure with a facial injury, the half-dozen arrivals will leave Gatland with a 46-man squad - two larger than Sir Clive Woodward's 2005 party.
The Lions have been maintaining a "one squad" mentality but All Blacks coach Steve Hansen pre-empted the call-ups and mischievously hinted at a split in the camp.
"I think he is about to bring a few extra players out to give himself the ability to play with two squads," said Hansen.
"He's at the stage where he wants to do that. I guess he will bring them out from the UK."
Lions lock George Kruis, however, claimed Hansen is in no position to comment on what is going on behind the scenes.
"He's entitled to his opinion and he's obviously a well-respected coach, but he doesn't know what's going on inside the camp," said Kruis. "He can have his own opinion but we've bonded pretty well.
"If we win, we celebrate together. If we lose, we're all upset. There will be a big emphasis on any new guys having to add to the group. They'll obviously be helped out in getting up to scratch."
- NZ Herald and Daily Mail
