Jadon Sancho, Mason Mount and James Maddison have been handed their first senior England call-ups as Gareth Southgate doubled down on his focus on youth in arguably his boldest squad selection to date.

Fresh from signing a new deal through to the 2022 World Cup in Qatar, the 48-year-old raised eyebrows on Thursday with his 25-man selection for the Nations League double-header in Croatia and Spain.

Exciting Borussia Dortmund 18-year-old Sancho has been selected for this month’s fixtures and becomes the first player born this century to be called up by the senior team.

Mount, on loan at Sky Bet Championship side Derby from Chelsea, and Leicester new boy Maddison have also been rewarded for his fine starts to the season, with Southgate is ready to unleash the youngsters against some of the world’s best.

“Well, it is (a big call) but I think it aligns with what we’ve done over the last 18 months, really,” the Three Lions boss said.

“We’ve got a few injuries in the midfield in particular – Dele (Alli), Jesse (Lingard) and Ruben (Loftus-Cheek) have been missing – and Fabian Delph, so there is an opportunity there.

“Then we have a decision on which way we want to use that opportunity. We think there are some exciting young players that we’ve been tracking, either through their clubs or our junior teams.

“It is a great opportunity for us to look at them. We feel that we are always conscious of the balance of how quickly we put those young players in and raise expectation around them and make sure that we don’t detrimentally affect their development.

“But we think they are performing well with their clubs, they’re confident players.

“We’d like to work with them now – they get an understanding of how we work, we get a closer look at them.

“Quite a few of them have trained with us at various times here anyway so we’re excited to see them.”

Injuries and a lack of game-time have led to Southgate’s changes as much as the form of those called-up, with Adam Lallana another big name left out.

But the England manager has always been ready to call on youth and would have selected Sancho anyway.

“With Jadon, I think we would be putting him in the squad regardless of injuries,” Southgate told BBC Radio 5 Live. “He’s a player that excites us a lot.

“He’s adapting to a big football club. He’s had two starts in the Champions League this year, he’s a player that is explosive, is really creative in the final third, has had a big impact in terms of assists in the matches that he’s played, can score goals.

“Had a big impact with our junior teams over the last couple of years and he’s really diligent without the ball. I like the fact he is not just a creative player that goes out and waits for the ball to come to him.

“At Dortmund he is required to do a job defensively for the team and he does it, so he’s an exciting player we’re looking forward to working with.”

Harry Winks, capped once, has returned to the senior team the day after starting for Tottenham against Barcelona in the Champions League, while uncapped Watford midfielder Nathaniel Chalobah is back in the squad after recovering from a long-term knee injury.

In addition, Ross Barkley’s upturn in fortunes at Chelsea means he is in line to win his first cap since the friendly against Australia in May 2016.

“Well, he’s had a long period injured at Chelsea last year, so that wasn’t a reflection on the quality of the player that he hadn’t been with us, but he wasn’t getting any football, really,” Southgate said.

“This year he’s started the season in the team at Chelsea.

“He’s a player that we know has good technical quality, is grasping the tactical side of the game – I was interested to read his interviews this morning on that – so it’s a good opportunity for him to come in.

“As I say, one or two of those opportunities might not have been there if we’d had other players available.

“But as always, when you get opportunities within the squad – people have come in, in the past, and done well and they stay in. That’s the way we work.”

Southgate spoke well of Daniel Sturridge after overlooking the Liverpool striker and insisted the door is still open to Joe Hart, despite plumping for uncapped Marcus Bettinelli and Alex McCarthy along with Jack Butland and Jordan Pickford.

Asked if the Burnley goalkeeper’s international career was over, the England boss said: “No, not at all. It’s continuity from the squad we picked last month.

“Jack started our last game so to suddenly leave him out of the squad because he’s playing in the Championship wouldn’t be appropriate I think.

“From Joe’s perspective, we don’t need to see Joe in a game at this stage to know what he can do.

“I think it’s great that he looks very settled. The move to Burnley has obviously worked for him – he looks confident in his game.