Mascherano (centre) had to be escorted from the pitch

Liverpool midfielder Javier Mascherano has insisted he does not understand why he was sent off in Sunday's 3-0 defeat by Manchester United at Old Trafford.

The Argentine appeared to question referee Steve Bennett's decision to caution Fernando Torres, and was then shown a second yellow card himself.

However, Mascherano said: "I do not know why I was sent off.

"When the referee showed me the second yellow card and sent me off I could not believe it."

Mascherano's dismissal carries a one-match ban but the Football Association may increase it as it aims to crack down on players showing dissent.

The 23-year-old's case will not be helped by the fact he completely lost his cool and would not leave the pitch until he was dragged away by Liverpool players and management.

Mascherano, however, believes he should not have been penalised in the first instance.

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"I asked the referee what was happening. I did not swear, I was not aggressive and I did not confront him," Mascherano told the Liverpool Echo.

"All I did was ask him what was happening, nothing else."

Liverpool were 1-0 down at the time of the sending off and Mascherano added: "I am sorry to my team-mates because that meant we went down to 10 men.

"That made things even more difficult for us."

After the match, Reds boss Rafa Benitez gave his support to his player, echoing his sentiments that nothing had been said to warrant a red card.

"Mascherano was surprised at the decision because he thought he said nothing wrong," said Benitez.

"Ryan Babel heard everything and told me Mascherano was just asking why Fernando Torres had been booked."

However, Benitez did admit that Mascherano had made a mistake in approaching Bennett.