Goalkeeper Christian Walton [Bury, on loan from Brighton and Hove Albion] and forward Chuba Akpom [Hull City, on loan from Arsenal] will also not be joining up with Gareth Southgate's Three Lions for the September double-header.
Southgate's side travel to Preston North End's Deepdale this Thursday (kick off 7.45pm) to take on a USA Under-23 team, who are gearing up for next summer's Olympic Games in Rio.
The U21s then travel to Norway where they will begin their Euro Qualifying campaign for the European U21 2017 Finals against the host nation on Monday, kick-off 6:45pm [local time].
Tickets for the game at Deepdale are priced at just £10 for adults and £5 for children, with a family ticket (two adults and two children) costing £20 and group bookings of 15+ working out at £5 for adults and £1 for children.
Season ticket holders at Deepdale can also claim half price tickets and concessions for U18s, over 65s and students (on production of valid ID) are £5. Call 0844 856 1966 for details or e-mail: email@example.com