The game against the 2019 Rugby World Cup quarter-finalists will be shown live and exclusively on Channel 4 and raises the curtain for the Lions’ eagerly awaited Tour to South Africa, which culminates in a three Test series against Rugby World Cup champions, the Springboks.

“We’re anticipating a tough game against Japan – a side that like to play at a high-tempo and shift the ball,” said Gatland.

“We saw throughout the World Cup they have attacking threats across the park and a solid defence and set piece.

“I’m pleased with the progress we’ve made during our training camp in Jersey so far, but we’ve a long way to go. You can see that the squad are starting to get to grips with our game strategies, but, as always with a Lions Tour, this takes time to bed in.

“We’re in a good place though and I can tell there’s a lot more to come from this group.

“Everyone in the squad will get a start before the start of the Test Series, so each member of the squad can put their hand up for Test selection.

“We are absolutely delighted to be playing in front of sixteen thousand supporters in Edinburgh. I’m sure the crowd will give the players an enormous lift before we depart for South Africa on Sunday.”

The Lions’ eight-game Tour to South Africa kicks off on Saturday 3 July when they play the Emirates Lions at Emirates Airline Park in Johannesburg. Three weeks later, Cape Town Stadium will host the opening Test match of the 2021 Castle Lager Lions Series – the first Lions Test in the Mother City since 1997. The British and Irish tourists then return to Gauteng and play the second and third Tests at FNB Stadium in Johannesburg on Saturday 31 July and 7 August respectively.

British & Irish Lions: 15 Liam Williams, 14 Josh Adams, 13 Robbie Henshaw, 12 Bundee Aki, 11 Duhan van der Merwe, 10 Dan Biggar, 9 Conor Murray, 8 Jack Conan, 7 Hamish Watson, 6 Tadhg Beirne, 5 Alun Wyn Jones (captain), 4 Iain Henderson, 3 Zander Fagerson, 2 Ken Owens, 1 Rory Sutherland. Replacements: 16 Jamie George, 17 Wyn Jones, 18 Tadhg Furlong, 19 Courtney Lawes, 20 Taulupe Faletau, 21 Ali Price, 22 Owen Farrell, 23 Anthony Watson.