The Three Lions boss thinks that Rashford is happy and himself again after meeting him over the summer and witnessing his recent performances under Erik Ten Hag at Old Trafford.
“I went and met with Marcus at the end of last season because I wanted to have a longer chat with him, given that we haven't had a chance really to sit and chat since the Euros previously,” Southgate told reporters.
“That wasn't because we hadn't tried to pick him, we had, so that period has been a long one given we have selected him in that period.
“I think he's showing signs with United that the enjoyment is back in his face, the joy of playing is back in his face. I've seen him arrive at the far post with a header which is quite staggering, really.
“So there are things that we've talked about over the years, I think there's a good structure to the team there. I think his pressing has also been aided by the structure of the team.
“I think he's still at his best coming from that left and when he's running in behind teams is when he's at his strongest.
“He's looking more like the player we've seen - I still think he can be even more and I hope that we can help with that and that we can benefit from that.”