Newcastle talisman Alexander Isak is becoming less affordable by the game

When Alexander Isak walked into the Emirates Stadium, a starry-eyed Arsenal fan quipped: ‘Welcome home, Alex.’ The Newcastle striker duly played like an intruder and was every bit as terrifying. Those stars soon made way for fear.

This is why Arsenal want Isak. This is why every club should want Isak, irrespective of whether they can afford him. He is an object of desire. Right now, he is doing whatever he so desires.

Isak has been playing well and scoring of goals of late, nine in his last eight matches before this tie. He scored again here but took his game to another level - ‘well’ would not do it justice.

Take the passage some 20 minutes before his opening goal. William Saliba thought he had defended it smartly, bringing Isak to a stop outside the penalty area.

That is where you want attackers, stationary and shepherded wide. What followed felt as if Isak had borrowed some starting blocks and swapped his boots for spikes, springing past Saliba from a standing start.

Saliba, for the record, was still in the starting position when his escapee broke into the area and pulled back for Lewis Hall, whose shot was blocked.

You could hear the collective murmur from the home masses. They were not knocking their man, more so building up the one in opposition. An object of desire, indeed. In that one moment he had shown the stealth of a jaguar and speed of a cheetah.

Meanwhile, at the other end, Arsenal were playing with a false nine in Kai Havertz, missing headers when unmarked from five yards. There is nothing false about Isak. He is the complete striker, evidenced by his recent goals.

Yes, he can score them like Thierry Henry, dribbles and fast finishes that take your breath away. But the sight of him nicking his last few from inside the six-yard area shows that a poacher resides within that athletic, whiplash frame.

His goal, in the 37th minute, was yet another example of his right place, right time instinct. There was still work to be done when Jacob Murphy’s poke ran through bodies and into his path in the goalmouth, not least because goalkeeper David Raya was throwing his body at his feet. But sizing the angle, Isak lifted in via the only means possible, the underside of the crossbar. It was a better finish than it perhaps looked, given the proximity to goal.

It is little wonder the TV cameras followed him off the pitch at half-time - they got closer than Arsenal’s defenders had during the first half. Those in red did not fare much better after half-time, either.

When Newcastle scored again six minutes after the restart, it was because of Isak, even if he was not the scorer.

That was Anthony Gordon, turning in from close range after Raya could only shovel a shot into his stride. And whose shot was it? Isak. Not just that, he had started the move from midway inside Arsenal’s half. So scared were they of him by now, it was in backing off that Arsenal allowed him to shoot.

It would be easy to say that he is the player who can transform Arsenal from contenders to winners of the Premier League. So easy it is said almost daily. But the more he plays like this, the less affordable he becomes. He is pricing himself out of a move!

Not that Isak will want to quit Newcastle. Not when they are likely headed for a Carabao Cup final. Not when they are likely headed for a return to the Champions League, too, the stage a player of his class demands. Fail to achieve the latter and we may have to revisit price tags this summer.

But, for now, he cannot want for much more than he has at Newcastle. For all of his heroics in attack, he must look at his comrades in defence and be thankful he does not have to find a way past them every week. They were equally heroic here. Indeed, he has team-mates of his quality in every area - from Sven Botman at the back to Sandro Tonali and Bruno Guimaraes in midfield and Gordon in attack.

For now, Isak should feel right at home on Tyneside, never mind North London.