There were an unusual number of training ground bust-ups last month that threatened to disrupt a club’s pre-season preparations.
Neymar intensified reports that he wants to sign for Paris Saint-Germain when he got into it with new Barcelona teammate Nelson Semedo last week.
And RB Leipzig called off their training session after Liverpool target Naby Keita left teammate Diego Demme in agony with a horror tackle.
The latest to get in on the act is Borussia Dortmund’s Ousmane Dembele, who had to be restrained from his teammates as he tried to confront goalkeeper Roman Burki.
The reason for Dembele’s frustration isn’t clear but he’s certainly upset over something, making repeated attempts to go after Burki.
Just as Neymar’s clash with Semedo fuelled rumours about his potential move to PSG, Dembele’s outburst is unlikely to quieten speculation surrounding his own future.
The 20-year-old has been heavily linked with a move to Barcelona, with Neymar’s possible departure clearing the way for Dembele’s arrival.
Watch: Dembele clashes with Burki
Whatever the cause of Dembele’s anger, it certainly won’t sit well with BVB chiefs. Watch the clip below.
Dembele is one of a number of players who have been touted as Neymar’s possible replacement, should the Brazilian complete a stunning £197 million move to PSG.
Barça have also been linked with Philippe Coutinho and, more tentatively, Kylian Mbappe.
Umtiti: 'I would welcome Dembele'
Samuel Umtiti confirmed Barcelona’s interest in Dembele in June and admitted he would welcome his compatriot with “open arms”.
"I know that Barcelona are interested in him," Umtiti told L'Equipe, per Goal.
"But all parties involved will have to reach an agreement. He would bring a lot to Barcelona with the quality he possesses and with the things he is capable of. I would welcome him with open arms.
"But I have not been discussing it with him. I will talk to him about it if and when it becomes official.
"Barcelona already wanted him last year and he knows what to expect. We will have to wait and see what happens.
"He is always welcome at my place, I will happily look after him."
Dembele enjoyed an impressive season at Signal Iduna Park in 2016-17, scoring 10 goals in 49 appearances, and is destined to play at the highest level.