Tottenham left-back Sergio Reguilon was heard directing a foul-mouthed blast at referee Craig Pawson during his side's 2-1 defeat to West Ham on Sunday.
Spurs fell to their fifth Premier League loss in their last six games, and now lie nine points behind the fourth-placed Hammers in ninth position in the table.
The pressure is beginning to increase on manager Jose Mourinho amid his side's dreadful recent form.
And judging by Reguilon's outburst the players are also feeling the heat.
A few minutes before half-time and with Spurs 1-0 down the on-loan defender was booked for pushing over West Ham's Jarrod Bowen.
But he clearly was not in agreement with Pawson's decision, and could maybe consider himself lucky not to have been given his marching orders given the language he used.
As he was shown the yellow card, Reguilon yelled in Spanish: "F****** hell mate. What card is that? God. A s*** card. Mother f*****."
Fortunately for Reguilon it appears Pawson does not speak Spanish, and allowed the game to continue without further action.
Reguilon was making his first appearance since January after recovering from injury.
But like the rest of his teammates he had an afternoon to forget at the London Stadium in what was a largely disappointing performance from Spurs.
Speaking after the game Mourinho gave a defiant defence of his tactics, and insisted his side were not in "crisis".
"Mine and my coaching staff methods are second to nobody in the world," he said boldly before going on to say: "I don't know what you mean by crisis.
"If crisis is frustration and sadness in the dressing room then I believe so and I think we all showed that.
"When a team fights the way the team did in trying to get a different result it's never a group crisis.
"A group crisis is when you're not together. I would say it's a bad run of results."
