Eric Dier's altercation with a supporter following Tottenham's FA Cup defeat to Norwich is being investigated by the Football Association.
It is understood the England midfielder's confrontation with an individual in the West Stand at the Tottenham Hotspur Stadium is being looked at.
The 26-year-old is likely to face disciplinary action from the FA over the incident.
Dier went into the crowd to confront a supporter who was arguing with the player's brother.
Tottenham manager Jose Mourinho said he understood why he did it, and hoped the club would not take disciplinary action against Dier.
It is understood Spurs will conduct a thorough review of the incident.
Mourinho said: "I think Eric Dier did something that we professionals cannot do but in these circumstances every one of us would do.
"Because when somebody insults you, and your family is there, and you get involved with the person that is insulting you, in this case a younger brother, I think Eric did what we professionals cannot do."
The incident happened in the area behind the dugouts, which is a corporate section, and Mourinho has criticised it for not housing "real Tottenham fans".
"Some are Tottenham fans but I think a lot of corporate," he said.
"A lot (are there by) 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 (real fans) are the ones who support the boys until the last."
Meanwhile, Mourinho will ask the club which of their next two games they want to prioritise.
Spurs visit Burnley tomorrow evening in what is a vital match in their bid to reach the Premier League top four, before heading to RB Leipzig needing to overturn a 1-0 deficit to keep their Champions League hopes alive.
They are in the midst of four fixtures in 10 days and are battling an injury crisis that is keeping Harry Kane, Son Heung-min, Moussa Sissoko, Ryan Sessegnon and Hugo Lloris out.
"I have to think about what's next," he said. "I have to speak with my club because I think some of these boys, to have a chance to fight Tuesday, they just can't play Saturday.
"I have to think about a Saturday and a Tuesday match and decide which one is the priority."