The Three Lions are back in action this month when they kick-off their EURO 2020 qualifiers against Czech Republic and Montenegro.
And four months on from their last game, which saw England beat Croatia at Wembley to reach the UEFA Nations League semi-final, Southgate admits the situation is different for a lot of his players with their clubs and there has also been the emergence of other options.
“It’s not been a straightforward selection, because we’re four months on from our last game,” he revealed.
“When you’re picking a squad, there’s got to be an element of what the players are doing with their clubs and what they have done with us.
“So you could look at Fabian Delph and say he hasn’t been playing for Manchester City, but he was our best player against Croatia.
“Trying to balance all of that has been difficult this time, no question, but we have qualified for a semi-final in the summer and it would be strange to make huge changes to that squad.”
One new face in the group is West Ham United’s midfielder Declan Rice, who only declared his ambition to switch his international allegiance from the Republic of Ireland to England in February.
He’s been in impressive form with the Hammers this term, and Southgate admits his selection was straightforward once the 20-year-old had outlined his intentions to play for England.
“His form warrants it,” said Southgate.
“There’s obviously been a well-publicised situation with Declan but we’ve tracked him for quite a while and I think they’re really big decisions when you’re asking a player to transfer associations.
“You’ve got to be really clear that you feel they have a future with you. That said, there was never any guarantees made to him. That was clear – you’ve got to be playing well to get in the squad.
“But his form has been excellent and we like what we’ve seen in terms of his personality, his character and his leadership qualities.
“He can play as a holding midfield player and also as a centre back so I think he’ll fit really well into the way that we work and we’re looking forward to welcoming him next week.”
The squad will link-up at St. George’s Park next Monday ahead of the first game with Czech Republic at Wembley on Friday 22 March.
There's still limited availability for the Czech Republic game in Club Wembley, where membership guarantees your seat for all England men’s senior internationals at Wembley.