Warren Gatland has called Tomas Francis and Gareth Davies up to his British and Irish Lions squad
No8 Ross Moriarty is the latest player to be ruled out of the tour with a nerve problem in his leg with Stuart Hogg already having been sent home and Jonathan Davies, Courtney Lawes, Owen Farrell and Sam Warburton all battling for fitness.
Gatland has therefore pulled Kristian Dacey, Cory Hill, Tomas Francis and Gareth Davies from Wales' two-Test tour of Tonga to join the Test match.
Allan Dell and Finn Russell will also travel from Scotland's tour of Australia with the Lions coach responding to widespread fan outrage by saying that their being in that part of the world already played a big part in their call-up.
"There's a bit of geography," Gatland said.
British & Irish Lions squad for 2017 New Zealand tour Tue, June 13, 2017
Express Sport runs through the confirmed Lions squad for the 2017 tour to New Zealand
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Express Sport runs through the 37-man Lions squad ahead of the New Zealand tour
"We did the same in 2013 and it was always part of the plan to cover a couple of Test lads.
"When you look at the positions we're covering – 1, 2, 3, second row, 9 and 10 – it's really hard in a Test week to back up and double up in those positions.
"We would have had players in the Test side having to sit on the bench on Tuesday night and then be preparing for Saturday.
"In 2013, we brought in some players from quite a long way away – Christian Wade was an example – who struggled for the first couple of days.
"Those players that are here coming from Wales and Scotland have acclimatised whereas players coming form Argentina they'd have left tomorrow and come in on Monday.
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"Those time-zones would have been particularly hard on them as individuals.
"We already had Cory Hill train with us back in Wales and knows the calls so that should help us in our preparation for next week and we've said all along this is about the Test series."
The four new British and Irish Lions are pitchside for today's clash with Maori All Blacks
The loss of Moriarty, even though he was unlikely to start ahead of Taulupe Faletau, is as much a blow to that preparation because he would have started on Tuesday against the Chiefs.
But an injury the Welsh No8 picked up in the very first game against New Zealand Provincial Barbarians will keep him out for more than a month.
"Ross Moriarty has pinched a nerve in his lower leg which the medics are saying is a minimum of six weeks," Gatland added.
"It's really frustrating for him.
"He picked up that injury in the first game and we've tried to get him through it but he's going to have a scan on Monday to see what the damage is but it's really unfortunate for him."