Cristiano Ronaldo reacted angrily to Rafa Benitez's decision to rule out one of his goals during training on Wednesday.
The 30-year-old was caught gesticulating on camera by television station Cuatro and shouting 'Vai Caralho!' in the direction of the Real Madrid coach.
The term is a Portuguese insult used to express disappointment and was followed by Ronaldo complaining that Benitez "gives everything against the Portuguese".
Later on he could also be seen displaying his frustration towards team-mate Alvaro Arbeloa as the team took part in a game where they were required to try and hit the crossbar.
Ronaldo said: "We're supposed to be putting the ball in there, the net, not this ****".
Benitez was recently asked who he thought was the best player in the world but resisted the opportunity to back the Portugal captain, leading to speculation about their relationship.