The Liverpool defender is still young enough to play for the U19s, but after his performances for the Young Lions last term and his impressive start to the campaign at Anfield, he is included in Southgate’s new-look squad.
England v USA
International Friendly Match
7.45pm, Thursday 3 September 2015
Deepdale, Preston North End
Live on BT Sport
Tickets: 0844 856 1966 or email@example.com
And the head coach admits he had no hesitation is selecting the former Charlton Athletic youngster, 18, to face USA’s U23s side in Preston next week and then for England’s first Euro 2017 Qualifier against Norway on Monday 7 September.
"Joe was a big decision for us, because we’ve brought him out of his age group," explained Southgate.
"But he played up an age group with our U19s last year and was the best defender in that group.
"He’s started exceptionally well at Liverpool and has coped with the move, playing Premier League football at Anfield with no problem.
"So we feel he’s in on merit and we feel the right challenge for him internationally is to be with the U21s."
Southgate has selected a 23-man squad, who will meet up at St. George’s Park on Sunday evening to begin their preparations for the Deepdale friendly on Thursday 3 September.
From there, the group head to Drammen where they will begin their quest to reach the next Euro Finals, which will be held in Poland in the summer of 2017.
However, Southgate will be without the services of Luke Shaw, John Stones and Raheem Sterling, who are all expected to be involved in Roy Hodgson’s senior squad.
But he knows that developing players for senior service is a major part of his role and wants the rest of the U21s group to see that as an inspiration for themselves.
"Ultimately, it is always Roy’s decision, it’s fine for me to pick who I want, but if Roy is picking players for the senior team then it’s pretty clear," he explained.
"From the start, John, Luke and Raheem will be with Roy’s team and, unless for some reason they aren’t involved, then that might be reviewed.
"But Raheem is already a regular starter for Roy and I would expect John and Luke will be really pushing in that area over the next year.
"The seniors have a European Championship next summer so it’s great for those players to be pushing for that."
This will be Southgate’s second Euro campaign, after leading the Three Lions to the Euro Finals in Czech Republic earlier this summer.
And with a number of the players involved over the previous two years now tipped to be challenging for senior places in the future, he knows how important their time with the U21s can be.
"Our job is to develop the next lot and the focus can’t just be about winning," he revealed.
"Yes, we want to win, but we’ve got to push the next group through and three or four of the squad from last summer will be with Roy now, with some good experiences behind them and experiences of what they had as a group and also what didn’t happen to them in the summer.
"That’s the nature of the role, as an U21 coach for club or country, you don’t always get your best players because they move up and that’s the landscape."
Tickets for the game at Deepdale are priced at just £10 for adults and £5 for children, with a family ticket (two adults and two children) costing £20 and group bookings of 15+ working out at £5 for adults and £1 for children.
Season ticket holders at Deepdale can also claim half price tickets and concessions for U18s, over 65s and students (on production of valid ID) are £5. Call 0844 856 1966 for details or e-mail: firstname.lastname@example.org