Eddie Jones has urged players to stake their claim on a starting World Cup spot when an England A side captained by Lewis Ludlow faces Scotland A at Welford Road on Sunday.
England defence coach John Mitchell takes charge of the team in the uncapped fixture.
Gloucester flanker Ludlow, 26, is one of 11 players in the starting XV yet to earn a senior international cap.
Leicester prop Ellis Genge - who has 28 England caps - will be vice-captain.
Scotland's team announcement has been delayed until Saturday, with nine players unavailable because of one positive Covid-19 test in the squad.
When the bus comes past, make sure you get on - Jones
The fixture is one of three in which possible future England stars will get a chance to impress head coach Jones while 11 of his usual squad are away with the British and Irish Lions.
It offers a chance to rebuild the side which fell to a fifth-place finish in the 2021 Six Nations.
After facing Scotland A, England have games against the United States and Canada in July and Jones says he will use this period to build towards the 2023 World Cup.
"We need fresh blood and we need fresh energy, and these guys have got one foot in the door and they've got to make sure they keep the door open," Jones said.
"They have the opportunity to become the permanent starter in their position. It's opportunity, and when opportunity knocks you've got to take it.
"When the bus comes past your door you've got to make sure you get on, because it might not come back again."
Umaga and Randall given chance to shine
Ludlow, who is participating in just his second England camp, said he was "definitely shocked" when he was asked to captain the side.
In the backs, Wasps fly-half Jacob Umaga finally gets his chance to shine on the international stage and will be in competition with Harlequins 10 Marcus Smith and Exeter's Joe Simmonds for Jones' attention, with the latter two competing in Saturday's Premiership final.
Umaga has been included in England training camps but is yet to earn a cap and will start alongside Bristol scrum-half Harry Randall.
Sale's Ben Curry - twin brother of Tom, who sprung onto the England scene during the last Lions tour - will start in the back row alongside Ludlow and Newcastle number eight Callum Chick.
Flanker Sam Underhill - one of the stars during England's run to the 2019 World Cup final - was unavailable for selection because of a concussion, while Northampton's Fraser Dingwall has a calf injury.
Genge is one of five Leicester players who will start the game at their Welford Road home, with prop Joe Heyes, lock Harry Wells, inside centre Dan Kelly and full-back Freddie Steward the others.
Sale hooker Curtis Langdon is also in the starting XV, as is England and Bath lock Charlie Ewels.
Ollie Lawrence - who made is England debut in October 2020 - is at outside centre with fellow England newcomer Max Malins on the left wing and Newcastle's Adam Radwan on the right.
Lewis Ludlam, Dan Robson and Joe Cokanasiga are some of the more experienced players named among the replacements.
England A: Steward; Radwan, Lawrence, Kelly, Malins, Umaga, Randall; Genge, Langdon, Heyes, Wells, Ewels, Ludlow (capt), B Curry, Chick.
Replacements: Blamire, Obano, Davison, Hill, Ludlam, Robson, Furbank, Cokanasiga.