Tottenham boss Jose Mourinho was left unhappy with Eric Dier after he climbed into a stand and confronted fans following their FA Cup shootout defeat to Norwich City.
An alleged altercation is said to have taken place between fans and Dier's brother.
In a video on social media, a close up shot of Dier shows the England star screaming: "He's my brother!"
Mourinho condemned Dier's actions in his press conference.
The Portuguese said: "I don't think that belongs to the game. The game was a fantastic representation of the FA Cup, but I cannot run away from the question.
"I think Eric Dier did what we as professionals cannot do but when someone insults you and your family is involved, especially your younger brother."
He added: "This person insulted Eric, the younger brother was not happy with the situation and Eric was not happy. We as professionals cannot do what he did.
"If the club discipline Eric Dier I would not agree with it, but what he did was wrong."
Other images showed Dier being held back by stewards before being taken away from the area.
Tottenham are yet to comment on the incident.
Mourinho also criticised that section of the stadium for not housing "real Tottenham fans".
"The people that are in these privileged positions by the tunnel," he added.
"Of course some are Tottenham fans but I think a lot of corporate, a lot of invitation, a lot of people with special status and probably it's the place of the stadium where I sometimes have doubts over if they are the real Tottenham fans because these are the ones who support the boys until the last."
Full footage of Eric Dier jumping over the stands and going over to confront a fan who was insulting & abusing his brother. Brotherly love, I respect that. pic.twitter.com/5xeSQ8Vj5a — FutbolBible (@FutbolBible) March 4, 2020