Doing the same at his club won't be quite so easy.
"But what I like about him is he's not going to fake his emotions".
Rashford will serve the first game of a three-match suspension this weekend following his red card against Burnley before the global break, further restricting his opportunity to build on his part in England's run to the semifinals of the World Cup in Russian Federation, where he made six appearances.
When he's available again after his ban, expect to see the 20-year-old Rashford mostly sitting on the bench and making frequent second-half cameos out on one of the wings.
Rashford is not alone when it comes to young English players struggling to get regular opportunities in the Premier League.
"He is a special talent", Southgate said.
The Red Devils boss was watching England take on Spain on Saturday as Marcus Rashford netted for the Three Lions in the 2-1 defeat to Spain.
Prosecutors file new charges against Paul Manafort, signaling a plea deal
Any deal would not be final until Manafort admits guilt before the judge, who would need to approve the plea. A mistrial was declared on the remaining 10 charges after jurors could not reach a unanimous verdict.
Rashford started both global matches in his favored position as a central striker, benefiting from attacker Raheem Sterling's withdrawal because of injury.
Like with so many others in the England squad, though, that confidence can only be maintained if Rashford plays for his club, no matter what he has achieved so far and the impressive comparisons he has drawn. "So I did it on objective", Mourinho said with a grin. "He will be a top player". Starts on the wing might be scarce, too.
In-form England striker Marcus Rashford has said he is determined to fight for his first-team place at Manchester United. He doesn't look at home on the right wing.
Rashford's development has also slowed considerably under Jose Mourinho after his dazzling breakthrough during Louis van Gaal's final season at United, though he delivered a reminder of his quality by scoring England's winning goal in a 1-0 friendly victory over Switzerland on Tuesday.
Kane had just come through loan spells at Millwall, Norwich City and Leicester City and, although he made his Tottenham Hotspur debut, also in the Europa League, having just turned 18, it was not until April 2014, when he was 20, that he made his first Premier League start - and scored. So where does Rashford actually fit in?
Those performances led to questions around Rashford's playing time at United, with former Liverpool defender Jamie Carragher saying he needs to leave if he ever wants to develop into a world-class striker.