Chelsea defender, Fikayo Tomori, remains eligible to feature for Nigeria.
Tomori was overlooked for England's two Euro 2020 qualifying matches against the Czech Republic and Bulgaria.
Although he was invited alongside club mate, Tammy Abraham, the defender was an unused substitute in both games.
Tomori would have become cap-tied like Abraham, if he had been summoned from the bench.
However, Southgate opted for Mason Mount, Jadon Sancho and Callum Wilson, as England thrashed Bulgaria 6-0 on Monday night.
At the moment, Tomori is well behind the trio of Tyrone Mings, Harry Maguire and Michael Keane in Southgate's pecking order of central defenders.
He is also eligible to feature for Canada, the country of his birth.