Dele Alli has withdrawn from England’s squad for the friendly against Switzerland on Tuesday with a “minor muscle strain”.
The Tottenham midfielder, who picked up the problem in Saturday’s 2-1 Nations League defeat to Spain, will be treated by his club rather than joining the Three Lions at Leicester’s King Power Stadium.
Both newcomers trained with their new team-mates at St George’s Park on Monday, having won promotion from the under-21s.
England wore the logo of Kick It Out during their morning session, with the Switzerland clash dedicated to the equality and inclusion organisation after 25 years of work.
Luke Shaw had earlier left the camp following the concussion he suffered in a nasty collision with Dani Carvajal at Wembley.
He had reported back to St George’s Park for monitoring but was released back to Manchester United after showing no ill effects.
Southgate is scheduled to address the media at 4pm, joined by Leicester defender Harry Maguire on his home patch.