"Everyone's known about Ruben's potential for a long time", the Tottenham star said post-game. It's not anything new to anyone.
The England midfield has often been accused of lacking the creativity to unlock the opposition but with fitness concerns over Jack Wilshere and his failure to secure a regular place in the Arsenal team, Southgate could have finally found the answer to that problem.
The youngster, on loan at Crystal Palace for the season, caught the eye at Wembley against world champions Germany on Friday night, earning the Man of the Match award for a confident display. Hopefully this [his worldwide debut] is another step in his progression.
"So it seemed as if there had been loads of pull outs and it's a bit messy, but actually it's been really tight and I think the performance - without getting too carried away - was a really encouraging one". He's a good boy and he still has a lot to work on, like all of us.
"He's quite a quiet lad, so I'm hoping he gets a lift in confidence from how we see him, the level we think he's capable of".
"Ruben is a big boy". It was a bit end-to-end, but I thought we showed real composure with the ball throughout the team. He's been the same since he was 12 I think!
"There's fantastic potential and hopefully he keeps working hard to fulfil it".
England supporters must have been dreading the prospect of facing Germany on Friday after seven key players including Harry Kane and Dele Alli pulled out of the squad.
"If we'd won it would have been better, but it was a tough game, and a good game from me to learn from". "Despite his size, appearance and the way he plays, he's not hugely confident at times and I think tonight it took him 10 minutes to have a look around him and think "all right, OK, I can do this".