Julian Alvarez pictured looking to the side while sat on the bench during Atletico Madrid's match against Villarreal in August.
Image caption, Julian Alvarez was a substitute in Atletico Madrid's second league match of the season against Villarreal on Sunday
Acrimony, anger and animosity; the Julian Alvarez summer transfer saga in a nutshell.
The boos aimed at the Atletico Madrid forward from his own supporters at the Riyadh Air Metropolitano Stadium on Sunday provided the latest twist in what has been one of the most bitter - and certainly public - storylines of the window.
And with deadline day on 1 September, the Argentine World Cup winner's future remains one of the hottest topics.
In simplistic terms the dispute comes down to this; Alvarez wants to join Barcelona - but Atletico won't let him.
The Madrid club's steadfast refusal to sanction the 26-year-old's dream move to the Spotify Camp Nou has led to one of the most rancorous public falling-outs in recent memory.
The feud led to Atleti fans jeering their own player on his return to club action after the summer World Cup in a 2-2 home draw with Villarreal on Sunday.
It had been anticipated.
Atletico Madrid president Enrique Cerezo, speaking last week, said: "I don't know if he will say sorry, but Julian is an excellent person and I am absolutely sure that he will win over the fans in two games.
"I said he wouldn't be sold, he's our player and an important part of our team. We like that he's with us and think he will have a magnificent season."
Nevertheless, the events that unfolded on Sunday certainly haven't gone unnoticed at Arsenal.
BBC Sport has consistently reported over the summer that Alvarez is viewed as the Gunners' dream transfer target.
But for the vast majority of the window, Arsenal's interest has been largely dormant because they were fully aware of his desire to join Barcelona.
They have been waiting for the right moment to strike and those at the Emirates are hopeful that time may be coming.
But is the deal possible?