The Borussia Dortmund midfielder is just 17 years old but has shone in the first few group training sessions before the arrival of the players from Manchester City, Manchester United and Chelsea who were involved in European finals.
And while Southgate’s main incentive was to build his experience ahead of the World Cup in Qatar next year and the tournaments beyond, he is increasingly confident he could have a part to play this summer.
“But for Jude,” Southgate pauses, “…he is phenomenal. Just in training in the last couple of days, to have a 17-year-old who wants to compete with senior players, not only has the techniques but the competitiveness and the maturity.
“He’s a hugely exciting player. He’s going to be an important player for England.
“I think we’re not just taking him for the experience.
“The experience is going to be enormous for him and for future England managers because I don’t see with him anything in his character that means he won’t succeed.
“His performance levels with Dortmund in the big Champions League games were the things that really struck us, you know?
“He stood up in those big moments and they’re the moments we’re really assessing the players on.”
Southgate also included Bukayo Saka – not so much for his individual performances this season, but more for the fact he produced them while his Arsenal side were struggling.
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“Well, firstly, he’s performed exceptionally well for us,” he said of the 19-year-old. “He’s performed well in a team that’s had a difficult season.
“Sometimes young players can go into teams that are playing well and flourish.
“But he’s gone into a team that have had a tough season and really played with character, as well as skill.”
Southgate named his squad for Euro 2020 on Tuesday and Liverpool’s Trent Alexander-Arnold was included as one of four right-backs in the final 26-man squad.