If one moment encapsulated the conundrum of Newcastle United’s summer, it was Alexander Isak entering the training ground only to have to pause as an ice-cream van made its exit.

The ice-creams were treats for his teammates’ children during a family fun day arranged by Eddie Howe. By the day’s end, however, the sweetness was replaced by a sour mood.

This discontent, felt by Isak towards the club and felt for him by fans, makes Monday night’s clash with Liverpool akin to igniting a firework in a powder keg. As Newcastle considers removing the Gallowgate End roof to refurbish St James’ Park, the explosive ambiance could very well start the renovation process.

But whom does he wish to see triumph? The club he aspires to represent or the one he is likely to remain with beyond September 2? This uncertainty complicates his reintegration.

Amidst the multitude of voices this summer, one word resonated above all—United. It came, with intention, from the head coach. On August 3, in the bustling corridors of Seoul’s World Cup Stadium, where even the walls perspired, Howe remained composed. He told me then, making all other noise negligible, that Isak had to ‘earn the right’ to join his teammates.

‘We are Newcastle United,’ he declared. These words might feature in a Wor Flags display on Monday evening, as the supporter group prepares to set the stage when the teams emerge into the arena. Howe would appreciate this—as he and his team hold Wor Flags’ work in high regard—but his primary focus that tense night in South Korea was delivering a global message—to fans, his players, potential recruits… and to Isak.

As Sir Bobby Robson once said, the name on the back means far less than the badge on the front. For Howe, too, no individual is more important than the collective spirit of a squad who have consistently outperformed the sum of its parts.

When Howe left that night for Seoul’s Incheon International Airport, he joked that a 14-hour flight without Wi-Fi might be a welcome relief. When he landed, all might be OK, a flurry of messages revealing that their transfer targets wanted to join and the clubs were willing sellers. That did not happen, of course.

There has since been progress with the arrival of defender Malick Thiaw and midfielder Jacob Ramsey, but still no striker. To sell Isak, they need two. That is extremely unlikely now, say insiders, coupled with a hardened resolve from the top to tell Isak he must stay. Even if open to the possibility, the board have never wanted to sell the team’s best player.

Nor has Howe. Because they believe, with Isak, the squad is not far away from competing at the very top of the Premier League. That is the frustration, that the player they identified three years ago, the player they have developed, the player who has three years to run on his contract, is the one player who is the missing piece in the jigsaw right now.

I stood with Howe and his backroom team in the middle of a parched training pitch in Seoul last month. At the time, the heat was on, in every sense. But to be there was also a reminder of the talent that resides – be that the coaches who have made full internationals of Anthony Gordon, Lewis Hall, Tino Livramento, Dan Burn and Joelinton, or the players in front of us who defied those temperatures during a session of intensity, energy and character.

Seeing new teenage recruit Park Seung-soo leave Fabian Schar in a heap signalled the end of my observation – they did not need any more headlines!

As the Far East tour went on, the improvement in mood and cohesion on the pitch was noticeable. On the first day, after landing to the story Daily Mail Sport had broken of Isak wanting to leave, the Singaporean sunshine made way for a storm. Howe and his players felt that battering. Their first, jet-lagged session was lethargic.

In an elevator at the team hotel, I told Bruno Guimaraes that Arsenal – that weekend’s opponents – had looked very sharp against AC Milan a few days earlier. ‘Oh, f******* hell!’ laughed the captain. In the end, they played well in a 3-2 defeat. But one week on, in Seoul, it felt different. Without Isak, it was interesting to note one drill in which Howe encouraged his midfielders to break the lines, and Guimaraes went clean through on goal more than once.

On the flight to South Korea, the majority of the players watched Happy Gilmore 2, and laughed a lot. Such moments were an escape from what Howe called the ‘constant noise’ around his team, a racket from which he has tried to protect them. On the evidence of last weekend’s goalless draw at Aston Villa, he has done a good job. With Isak – or any striker – Newcastle would have deservedly won that game.

And so that comes back to the feeling of regret felt by Howe, his players and supporters – of Isak, a Newcastle player, refusing to play. They bossed and beat Liverpool in last season’s Carabao Cup final, in which Isak scored. It will, in football terms alone, be far harder to do that without him. Even so, it is because of him, in a roundabout way, that they still stand every chance of beating Liverpool. His actions this summer have guaranteed that a bear pit awaits.

A sour taste lingers on Tyneside, but getting one over on Liverpool would be the sweetest sensation of all.