Real Madrid legend Iker Casillas has taken aim at Manchester United boss Jose Mourinho.

Now with Porto, Casillas has responded to Mourinho's claims that he would talk behind he former Real coach's back.

After Liverpool defeated United, Casillas stated: "According to a Portuguese daily, someone said that a 37-year-old player like me is at the end of his career.

"I totally agree! My question to this publication is that in the case of a coach, when, and at what moment to they see that they're no longer capable of coaching a team?"