With many of their expected hefty English contingent set to contest their domestic final at Twickenham seven days before their opening game in South Africa, the Lions' preparation will again be compromised.
Two of the three tests between the Springboks and Lions will be played in Johannesburg at altitude – the first of those at Soweto's Soccer City venue where the All Blacks set a record crowd of 94,700 in their dramatic 29-22 victory over the Boks in John Smit's 100th test in 2010.
The second test will be played in Cape Town; the third at Ellis Park, South Africa's spiritual home of rugby which leaves traditional rugby strongholds Bloemfontein and Pretoria to miss out.
The combined capacity for the three test venues is just below 205,000, which could make the 2021 tour the best-attended of the professional era, potentially surpassing the 192,972 who attended Australia in 2013.
Unlike the New Zealand tour, the Lions will play no mid-week fixtures between tests.
The Lions, led for the third time by now Chiefs coach Warren Gatland, will also play three Super Rugby teams – the Sharks, Stormers, Bulls – and two further games against South Africa A and an invitational team.
"I am absolutely thrilled," Gatland said. "Ensuring the team are absolutely primed for the test matches is a critical element of any Lions tour and I am confident the quality of opposition we will face in the opening weeks will get us ready to take on the Springboks."
"We are very comfortable that three of the games, two of which are test matches, will be played at altitude.
"Our schedule falls in a way to allow us to start at sea level before building up and acclimatising to the unique environment that playing at altitude presents."
Rassie Erasmus coached the Boks to World Cup glory last month but has since assumed his director of rugby position and is not expected to be in charge for the Lions tour.
"There are players who have been to three Rugby World Cups and finished their careers with a winner's medal yet never got to play against the Lions," Erasmus said.
"They only come around every 12 years for our players and only a few of them ever have the privilege of wearing the Springbok jersey in a Lions series.
"Warren Gatland is a massively experienced and astute coach with a phenomenal record with the Lions and the rugby experience for our players and public will rival that of a Rugby World Cup."
British and Irish Lions tour of South Africa 2021:
3 July - Stormers (Cape Town Stadium)
7 July - South Africa Invitational (Nelson Mandela Bay Stadium, Port Elizabeth)
10 July - Sharks (Durban)
14 July - South Africa 'A' Team (Mbombela Stadium, Nelspruit)
17 July - Bulls (Loftus Versfeld, Pretoria)
24 July - First Test v Springboks (Soccer City, Johannesburg)
31 July - Second Test v Springboks (Cape Town Stadium)
7 August - Third Test v Springboks (Ellis Park, Johannesburg)