Claudio Ranieri accused Aboubakar Kamara of disrespecting his Fulham team-mates, supporters and the club itself by ignoring instructions and taking the missed penalty that almost cost them victory against Huddersfield.
Fulham secured three vital points with a 1-0 win against a rival for relegation when Aleksandar Mitrovic scored in stoppage time, having earlier been ignored by Kamara as the club's senior penalty taker before Kamara's tame effort was saved by Jonas Lossl at 0-0.
Kamara had earlier this month scored from the penalty spot in the 4-1 defeat at Manchester United but the 67-year-old Ranieri was uncharacteristically incensed that he "thought only of himself" — and could yet drop him for something he insists he has never previously encountered.
"It is not possible to explain what happened after we got the penalty, or maybe I should say it is easy when a man thinks only of himself," the Fulham manager said.
"It is not right. He didn't respect me, the club, his team-mates, the crowd. He took the ball, and just said 'I want to shoot'. He didn't listen to reason.
"I have spoken a little to him. I think he didn't understand what I said. Mitrovic was the designated taker, but Kamara scored our last penalty and took it on himself, 'I am the man'.
"He did not apologise, he just told me 'I wanted to shoot'. I said to him 'If the whole team just said I want to shoot, what would happen?' It is impossible to speak to this man.
"He did not understand the reason; for him everything is fine, we won the match. It is unbelievable; the first time in my life I have seen that.
"I understand why the fans might boo him, but of course it is better if the fans and us are altogether. I just did what I had to do. You must respect the nominated taker.
"I hope he can understand; it is clearly difficult. I don't know if that is it, if it is finished or if it will continue. Maybe I will take him away from the squad.
"But I will do what is best for the squad. If it is good for them, he plays. If I think it isn't, he comes out. We'll play the Arsenal match (on Tuesday), then I decide.
"The other players are calm because we won – but not me. It is not important whether we won or lost, it is important what you did and why."
Mitrovic's late finish left Huddersfield bottom of the Premier League, having lost all seven of this month's league fixtures, and their manager David Wagner said: "Obviously it's a low point.
"Not only because we've lost seven in a row but how we lost it. It's a heavy loss we've conceded (at Fulham). We will need for sure a little bit longer than only 30 minutes afterwards to deal with it.
"December wasn't our month, obviously. But for me it's not possible to think so quickly after the game about the transfer window or the next game. I have to reflect.
"It's very difficult."