The British & Irish Lions have reached an agreement reached with Premiership Rugby for the release of all players at the conclusion of their domestic commitments for the warm-up game against Japan on 26 June.
The English players will also be available for the Lions' planned training camps ahead of the Japan fixture at Murrayfield.
"I would like to thank Premiership Rugby, as well as PRO14, for their support in agreeing to release players for the Lions," Lions coach Warren Gatland said in a statement.
"I have always said that preparation is key to a successful Lions tour, so today's news is very welcome and something we are appreciative of."
Jason Leonard, chairperson of The British & Irish Lions, added: "We are very grateful to Premiership Rugby and PRO14 for the release of players after they have concluded their domestic commitments.
"In particular we would like to thank Phil Winstanley for his diligence in helping us reach an agreement."
The Lions take on the Brave Blossoms in Edinburgh, the first home game they have played since facing Argentina in 2005. Gatland's charges then head to South Africa for the 2021 Lions series.
Premiership Rugby added: "We know how much the Lions tour means to rugby fans and players and we wish the Lions every success. We are sure our players will make a huge contribution."
The Lions tour to South Africa is scheduled between 3 July and 7 August.