Still a few players who must be on Southgate's list of potential call ups, especially if any of the initial squad are injured including I'd guess :
GK - Marcus Bettinelli, Nick Pope
Defenders - Chris Smalling, James Tarkowski, Lewis Dunk, Phil Jones, Luke Shaw, Wan-Bissaka
Midfield - Andros Townsend, the infamous Jack Wheel chair, James Maddison, Mason Mount, Adam Lallana, Lewis Cook (should now be fit ?), Demerarai Gray
Forwards - James Vardy, Tammy Abraham, Danny Ings
Then there are the current E u21 squad.
Not saying they are great players, but Southgate has more options than are often thought - and all (bar Wheelchair ?) of these have been called up in the last couple of years