Radamel Falcao's former agent Silvano Espíndola has revealed the striker recently played the Under-21 game against Tottenham fearing he would suffer a new injury due to the aggression of lower-tier football.

Espíndola was the agent who brought Falcao from Colombian side Lanceros Boyacá to River Plate in 2001 and, even though the United star is now represented by Jorge Mendes, the pair still keep a strong friendship.

During an interview with AS Colombia, Espíndola has admitted the striker is not happy at all at Old Trafford while revealing their surprising conversation before Falcao was named in the United under-21 squad to face Tottenham on 10 March, just one day after being an unused substitute in the FA Cup game with Arsenal.

Espíndola reveals Falcao faced the game with fears over an injury, not because he had any fitness problems but because last season he tore the anterior cruciate ligament in his left knee in similar circumstances, while playing in Monaco's French Cup tie against fourth-division Chasselay.

"That injury is already forgotten. The problem lies in the intensity of play, he is not yet at his top. He has to return to that intensity. He is not afraid of a new setback but needs more pace," Falcao's former agent said.

"When he was on his way to the stadium to play that game with the youth side he called me. We talked about 20 minutes and he said: 'I have never had to live something like this, I do not know how to handle it. I feel weird.'

"Furthermore he was a little bit cautious because he is afraid of those games against youth sides or second and third division teams. In those divisions they are used to hitting you a lot and making strong tackles. It was like that how he got injured in France, against a fourth division side.

"And I want to clarify that Falcao already knew [he was going to play only 70 minutes]. Van Gaal had told him before the game."

Espíndola also criticised van Gaal for how he dealt with the situation, prompting suggestions the boss wanted to humiliate the striker.

"If the Dutchman had clarified [the fact that Falcao would be substituted], people wouldn't have believed Falcao's level is that bad, that he can't even play a whole fame against a youth side. Van Gaal never clarified that and it created speculation.

"But Falcao is not going to say anything because he doesn't want to make Van Gaal look bad. That's admirable. He does not want to generate controversy. He wants to work and waits for his chance."

However Espíndola claimed that, even though Falcao is obviously not happy with his situation at Manchester United, he has never said anything bad about van Gaal and hasn't revealed his intention to move somewhere else in the summer.

"He is sad. I cannot deny that. My job is to motivate him. But he never complains, he has no bad feelings to anyone. He always has the same attitude. He is in a very difficult moment of his life but still trains every day as if nothing happened.

"He is very reluctant to speak about his future. We have not spoken of any offer because he prefers to stay focused on regaining his level at Manchester United. There is a club that have always been behind him, I will not say which one, but it is a club that has been monitoring his situation. But right now there are just rumours."