Despite Wednesday’s 1-0 win over Austria, things didn’t quite go according to plan for the Three Lions boss.
Yes, there were some encouraging performances from teenagers Jude Bellingham and match-winner Bukayo Saka, as well as Jack Grealish who continues to build up his fitness.
Yet an injury to Trent Alexander-Arnold, which subsequently ruled the Liverpool right-back out of this summer’s tournament, and the continuous absence of Jordan Henderson posed problems.
Alexander-Arnold was part of Southgate’s 26-man squad, despite some questioning the logic of taking four right-backs, including Kieran Trippier, Kyle Walker and Reece James.
Perhaps it was overlooked that Walker and James may be more accustomed to playing as a right-sided centre-back if England do switch to a back three, with Alexander-Arnold and Trippier providing the options at wing-back.
That scenario has changed, though, following Alexander-Arnold’s setback. The question now is, who will replace him?
Southgate will decide after Sunday’s match against Romania (5pm kick-off) which of his standby players will take up their place in the 26. Ben Godfrey, Ben White, Jesse Lingard, James Ward-Prowse and Ollie Watkins are the five outfield men in contention.
The aforementioned players include two defenders, two midfielders and one striker, meaning Southgate has most options covered.
If the England boss is looking for defensive cover to compensate for the loss of Alexander-Arnold, the most like-for-like replacement is Everton’s Godfrey.
The 23-year-old predominantly played at centre-back for the Toffees during the 2020/21 season but also played on the right and left side of defence.
Brighton centre-back White, 23, must also fancy his chances of a late call-up if Southgate wants another centre-back option, which may mean James is seen more as a wing-back if England operate with a back three.
White also has the advantage that he has played as a holding midfielder, the position he took up after coming on against Austria for the final 19 minutes.
With question marks over Henderson’s fitness, England do look a little light in the middle of the park, where Declan Rice and Kalvin Phillips have also recently returned from injury setbacks.
It will be interesting to see if and where White is used on Sunday.
Against Austria, though, Southgate did set his side up with a back four, which included Bellingham and Rice as the two central midfielders in a 4-2-3-1 system.
Ideally, the England boss would want to hand minutes to Henderson and Phillips in that area, while Ward-Prowse and Lingard will be hoping for a chance to force their way into the squad.
Due to injury concerns, particularly with Henderson who hasn’t played a competitive match since February, it may make more sense to call up Ward-Prowse or Lingard to replace Alexander-Arnold.
But would that suggest Southgate is going back on his decision to name four right-backs in the original squad?
Manchester United quartet Marcus Rashford, Harry Maguire, Luke Shaw and goalkeeper Dean Henderson have also joined up with the squad following their Europa League exploits.
Maguire’s fitness is also a major concern as he continues to recover from an ankle injury.
That will also play a part in Southgate’s decision making.