Marcus Rashford can do no wrong at the moment. Debate may rage among the managers in charge of the various aspects of his rapidly developing career over his readiness for international football or the likelihood of his supplanting Wayne Rooney or Zlatan Ibrahimovic in the near future at Manchester United, but as long as he is scoring goals a striker is always in the right.

The teenager’s response to being sidelined at United was to come on as substitute and score a late winner at Hull. Left out of Sam Allardyce’s first England squad a week ago, he dropped into the under-21s and rather splendidly bagged a hat-trick against Norway on Tuesday, not only impressing the watching England manager in a 6-1 victory but gently reminding Gareth Southgate – who had reservations towards the end of last season – that he is mature enough to deal with any situation that comes along and is far from being overawed by the “exposure” involved in playing in front of a crowd of 8,454 in Colchester.

Already there are people screaming that Southgate is not fit for purpose if he cannot recognise ability when he sees it, as well as pointing the finger at Allardyce for not being adventurous enough to include a rising star in his squad. Though it is less easy to ridicule José Mourinho over his team selections there is a certain amount of disquiet at Old Trafford that a bone fide home-grown talent is losing game time.

These are legitimate concerns, yet none of it really matters as long as Rashford keeps on finding the net. United couldn’t win the game at Hull without him, could they? Then he came on and suddenly a frustrating evening turned into three points. Mourinho probably did not get where he is today by ignoring that sort of thing. All Rashford needs to do is carry on and, unless the United front line responds to the challenge from its own bench by upping the goal rate so that substitutes find it hard to get a look in, everything should work out fine.

Faced with a choice between dropping his captain, one of his statement signings in Ibrahimovic or an 18-year-old prodigy with plenty of time on his side, Mourinho made a smart choice. Let the youngster watch and learn. If the two first-choice front men hit it off and win matches for United, Rashford will have plenty to learn from. What 18-year-old would not want to be in a position to take advantage of the advice and experience Rooney and Ibrahimovic have to offer?

If, on the other hand, two strikers in their 30s struggle to make an impression on opposing defences, what better option to have on the bench than a confident teenager anxious to make the most of every opportunity? Mourinho is in a win-win situation, precisely because Rashford has so much time on his side. The Portuguese’s record on promoting youth players may be questionable, and perhaps something of a sore point considering the lengths to which he recently went in a flawed attempt to defend himself, but he is not about to turn his back on a match-winner. The pressure is on the older players to justify their inclusion ahead of a talent such as Rashford.

While Ibrahimovic is older than Rooney, it may be the captain who has most to prove, particularly as Mourinho went out of his way to insist he sees him as a striker and will have no truck with roving briefs in midfield. United now have Paul Pogba to perform that function in any case. Mourinho has granted Rooney his wish, to be played in a forward position and now it is up to the player to show he can still score or make goals (as he did for Rashford at Hull, in fairness). If Rooney can, even his many critics must accept that Rashford must learn to be patient. If Rooney cannot, Rashford will get his chance, and as long as he maintains his upward trajectory no one could possibly complain.

Catch me if you can: Marcus Rashford celebrates his late winner at Hull, with Wayne Rooney and Zlatan Ibrahimovic in pursuit. Photograph: Matt West/BPI/Rex/Shutterstock

It is a similar story with England. It matters not a jot whether Rashford is in Allardyce’s plans right now – although he is bound to be more at the forefront of his thinking than a week ago – because no harm was done in Slovakia and the next tournament is two years away. That Rashford is older now than Michael Owen was at France 98 is neither here nor there. Owen broke through at the perfect time and the perfect age to feature impressively at that World Cup, but Rashford did not make quite as pressing an argument for first-team inclusion at the European Championship just completed.

Most people were relieved to see him make the squad and he did not do his reputation any harm when he came on as a substitute, but in advance of the matches few were in favour of him displacing Rooney or Harry Kane in the starting lineup. With hindsight it might be felt England could have gone further had Roy Hodgson been willing to take a risk and Rashford had taken his scoring form to France, though it sounds like the wildest of wishful thinking to imagine a teenager with just a handful of Premier League starts to his name could have transformed England’s sorry Euro campaign.

The main thing to focus on now is that Rashford’s England career is up and running and he will still only be 20 when the 2018 World Cup in Russia comes around. If he is not a feature of the England team by then, and he has maintained his club form, then it might be fair enough to blame Allardyce for a blind spot. Like Mourinho at United, Allardyce was sensibly putting his trust in the old guard for his first England game. He did not make a mistake by leaving Rashford at home, particularly as the player’s weekend did not exactly go to waste.

Let’s look at the positives from this situation instead. Rashford did not sulk or spit the dummy about joining the under-21s, he simply got on with it and acquitted himself well. It could be argued that his hat-trick was achieved against inferior opposition but England teams at all levels have played plenty such opponents in recent years and hat‑tricks remain unusual.

In Slovakia, England were sluggish and somewhat timid, suggesting once again that they tense up unhelpfully when they need to win games. That is a problem for Allardyce to solve, as is the fact that neither Rooney nor Kane bothered the Slovakia defence unduly, but the manager now has a home game against Malta to make a few changes if he likes and a goalscoring forward who has made a strong case for inclusion. At this stage of the season, and at this point in the qualification campaign, what more could anyone ask?