Manchester United won 2-1 against Middlesbrough on Saturday.
Southgate said: “A year on, the side has matured.
“They were quite a young team last season but they seem to have more steel about them.
“They have got so many attacking options within that side and the type of football they play is fantastic to watch – there is so much good about what they do.
“Paul Scholes is as good as he ever was and it is a huge loss to England that he didn’t carry on.
“He is still good enough, without question. In the period I was playing he was the best England player. He is an outstanding player – he can do everything.”
