GARETH SOUTHGATE has told his “fearless” stars: You don’t know how good you can be.

The England squad’s average age is 26, their third youngest ever at a World Cup.

4 Gareth Southgate has picked a youthful England squad for Russia 2018 Credit: Getty Images

And boss Southgate said: “I see such exciting players coming through.

“I don’t think they know how good they might be.

“I was looking at Ruben Loftus-Cheek a couple of weeks ago at Crystal Palace. He’s having a huge impact on the game and there’s still more to come.

“He’s 6ft 4ins, technically outstanding, he can beat players, dribble past players, retain the ball and slide passes.

4 Southgate reckons Ruben Loftus-Cheek could have a big impact for England Credit: Reuters

4 Liverpool star Trent Alexander-Arnold is in the squad at just 19 years old Credit: PA:Press Association

“I’m thinking ‘go on, go again’. He just needs to keep progressing and time to do that.

“That applies to so many of them. That’s the beauty of the age they’re at.”

Only five of the England squad were in Brazil for the disastrous 2014 World Cup and keeper Nick Pope and full-back Trent Alexander-Arnold are both uncapped.

Southgate said: “I don’t see it as a gamble and I don’t think being free of inhibition is gambling.

“I think it’s being fearless in how we want to play, being brave enough to put people in and not think ‘well, he’s the best player but he’s young, maybe we should pick a lesser player who’s a bit more experienced’.

“You can make excuses at times for not putting young people in.

“You accept they’ll make mistakes because of the way we’re asking them to play.

“There’s not a player in the squad I would have any concerns about starting in the first match. That’s why we have picked them.”

Gareth Southgate explains his choices for the England World Cup squad

4 Harry Kane or Jordan Henderson are set to skipper the Three Lions Credit: PA:Press Association

CHARLIE WYETT'S ENGLAND TEAM TO STAR VS TUNISIA Pickford, Walker, Stones, Maguire, Trippier, Henderson, Loftus-Cheek, Young, Sterling, Kane, Lingard.

Southgate claimed the Three Lions are disadvantaged by the lack of Englishmen playing in the Premier League.

He said: “Maybe it’s brave to take players without a number of caps but we have to give these guys belief.

“We’re picking them not because they’re young but because they are the best in their positions.

“We pick from 33 per cent of the Premier League. It is quite unique.”

Southgate was also unimpressed by the FA mocking Harry Kane.

A tweet after Manchester United’s 2-1 FA Cup win over Tottenham asked Chris Smalling “What’s in your pocket?” and featured a clip of him saying “Harry Kane”.

Southgate added: “There was a good internal discussion and we made an apology pretty quickly to Harry and to Tottenham.”