How Thomas Tuchel handles the relationship with Jude Bellingham could define his time as England head coach, and ultimately it could have a huge bearing on how far England go in next summer’s World Cup.

That’s how important the dynamic is between the national team manager and the country’s biggest star.

And despite Tuchel saying directly there is no problem between him and Bellingham, there is still some mystery around the player’s role with England, how he integrates with his team-mates off the pitch, and how the atmosphere within the squad is totally different when he is not around.

Bellingham has exacting standards. He is a perfectionist. And he demands the very best in all around him.

That was evident in the Euros final in Berlin, when he berated Gareth Southgate on the touchline, mid-game, for not making the tactical changes that he – as a 21-year-old player – thought were necessary.

Anthony Gordon has spoken openly about how the England camp is a different place, with and without Bellingham.

“You definitely notice when he is not here because he is such a big presence, such a big player,” said the Newcastle winger.

“But he has been injured, he has had a tough couple of months and it’s probably done him some good to be honest, because he has played so much football for his age.”

Gordon is absolutely right. Bellingham has already played 282 club matches and earned 44 international caps – that is extraordinary for a 22-year-old.

Gordon also makes a relevant point when he refers to Bellingham missing the September camp because of a shoulder operation, and that he is still working his way back to full match fitness. Tuchel was correct when he said the No 10 has yet to play a full 90 minutes for Real Madrid since his surgery.

But, conversely, he has been fit enough to feature in five Madrid matches in 15 days, and there is an argument that he needs match time right now, for club and country, in order to regain full fitness, after playing no football for nine weeks in the aftermath of the Club World Cup.

Crucially, fitness wasn’t the reason Tuchel gave for leaving Bellingham out, and the player himself made it clear to the boss that he wanted to join up.

The England boss’ honesty and brilliant oratory with the media is to be applauded. It would have been easy for Tuchel to say that Bellingham isn’t fully fit, and so everyone thought it best he sit this one out.

Instead, he told us he decided to leave Bellingham at home. It sounded like a snub, but Tuchel insisted it was only right that, following the really impressive 5-0 mauling of Serbia in Belgrade last month, the same squad had earned the right to have another go. And this is where there is an apparent contradiction.

Tuchel has repeatedly bemoaned the lack of time he gets with his players building up to next summer’s North American extravaganza.

At the moment Tuchel took charge on New Year’s Day, he pointed out that he only had six international camps to get to know his players, work with them closely on and off the pitch, spend time with them, build a philosophy and mould them into World Cup contenders.

That seems at odds with his decision this time to leave out some of the biggest names, who he will surely rely upon next June.

As well as Bellingham, you can include Phil Foden in that assessment for sure, probably Jack Grealish, and maybe Adam Wharton.

Bear in mind too that Tuchel felt John Stones’ presence was so vital and so sorely missed in and around the England squad, that he invited the Manchester City defender to come along with the group to the summer training camp near Barcelona, even though he was injured and he couldn’t join in on the grass.

Tuchel wanted him around the place, building a bond. No such invitation was extended to Bellingham this time round, when he is training fully.

Tuchel is still adapting to life as an international manager, and he has talked at length about how it is a struggle not having the day-to-day contact with his players that he has always enjoyed at club level.

Why then, when you have such limited time, would you so pointedly drop a generational talent like Bellingham and not include him in your plans?

Bellingham has played in only four matches under Tuchel so far. Now that he is missing this camp, there is a maximum of four more England games to come before the head coach has to select his World Cup squad.

We are not privy to the conversation between Tuchel and Bellingham on the phone last week. All we know is what the England boss told us: that the Real Madrid superstar made it clear he was fit and wanted to join up with his country, only for the German coach to tell him he wouldn’t be selected this time.

Tuchel was sticking to his guns, and to a promise he had made to the squad at the end of the Serbia game in September, when, after the team’s best performance since he took charge, he said he would bring them all back in October.

The costs of that promise in terms of the relationship with Bellingham might not be fully understood until we get to the World Cup.

This international break was the first opportunity for the two men to sit down and clear the air, discuss what happened four months ago, when Tuchel said his mother is sometimes “repulsed” by Bellingham’s behaviour on the pitch.

Tuchel has since apologised for those comments – both publicly, and to Bellingham in private – and made it clear he absolutely meant no offence, and had chosen his words mistakenly.

He bristled when I brought the subject up again in the latest England news conference. But the fact of the matter is, the two men haven’t been together in person since that flare-up, and whilst a call-up wasn’t possible in last month’s international break as Bellingham was injured, Tuchel has pointedly refused the opportunity to have a face-to-face reunion now.

The England manager often says that he doesn’t need to see many of England’s “special” players in person, in camp, because he is fully aware of what players like Grealish, Foden and Harry Maguire can do.

He doesn’t apply that same philosophy to the England captain, however, who is always included for his country even when, like now, he is struggling with a knock.

Harry Kane had to sit out some of the more energetic recovery session antics at St George’s Park on Monday, as he nurses his body towards the friendly with Wales on Thursday.

So why does Tuchel feel it vital that Kane be a part of the group, with his exceptional leadership skills and standard-setting, but not Bellingham? Most England fans would agree that both players are equally vital to England’s chances at the next World Cup.

When away with England, Bellingham’s closest companions are Jordan Henderson and Trent Alexander-Arnold. Trent is injured right now, and there are no guarantees he will make the plane for next summer’s World Cup with so much competition at right back.

As for Henderson, it is a key part of his England role that he sets standards on and off the pitch, stewards and cajoles the younger players – Bellingham included.

That support network around Bellingham is vital in getting the best out of him. Tuchel is acutely aware of that when he selects his squad.

It is important to reiterate that the England head coach is adamant he has a good relationship with Bellingham. I asked him that question directly at Wembley, and with a steely look in my direction, he gave an unequivocal and pointed response.

The last thing Thomas Tuchel wants is for outsiders to stir up tensions and cast doubt over his relationship with a player who is so vital to his and England’s fortunes.

But after Tuchel’s bizarre comments in the summer, and his equally surprising decision to leave Bellingham out of this England squad, those doubts will remain.