Manchester United were firmly in the match against Chelsea, until Lisandro Martinez's moment of madness left Michael Carrick's side on their knees

Lisandro Martinez has been blasted for "letting everybody down at Manchester United" and told his red card was "unacceptable" after he conceded a penalty for mindlessly jumping into Wesley Fofana.

Michael Carrick's side were the better team in the first half and would have been 1-0 up at half time had Matheus Cunha not strayed into a marginally offside position before finding the net. In the second half, Martinez was at fault for Chelsea's first goal, as Morgan Rogers got past him too easily before scooping a fine finish over Senne Lammens.

However, a few moments later, the Argentine struck Fofana in the face in the box as he challenged him without even looking at the ball, conceding a penalty and earning himself a second yellow card in the process. After he was dismissed, TNT Sports commentator Ally McCoist tore into the Argentine.

Make sure you never miss the latest Manchester United news and opinion by making Manchester Evening News one of your Google preferred sources

After a Chelsea corner was swung to the back post, Martinez had his back to the corner when he collided with Fofana. The referee did not see the incident, but VAR intervened, leading to Martinez's red card.

When the replay came up, McCoist said: "Ridiculous defending, you're just jumping into him, that's a penalty. Somebody explain to me why that's not a penalty?"

Not long after the decision was made, McCoist added: "It's unacceptable, absolutely unacceptable. He runs right across, look, absolutely crazy, crazy. He's let everybody down, teammates, everything."

Joe Cole, who was also on punditry duty, said: "You know the players' mindsets, he's been embarrassed by Rogers, I think this'll be given. We know how he sees the club and the situation, it's rash. We're talking about the action, it's rash, crazy."

McCoist then added: "Exactly who I'm thinking about right now, Michael Carrick. Look at that. He can't look at him and nor should he. He's not looked at him and nor should he."

Only one minute and 22 seconds separated Martinez's first and second yellow cards. His implosion all but ended United's hopes of getting back at Stamford Bridge.

Carrick's feelings on the Argentine could be inferred by the fact he did not even acknowledge him when he trudged down the tunnel. Ex-Chelsea forward Joe Cole, who was on punditry duty in West London, also suggested Martinez's days at Old Trafford should be numbered.

The ex-England international said: "The new Manchester United, Martinez has ran his course. Far too often in a Man United shirt, it happens, he's at the scene of the crime too often, at fault too often and I think that's his time done."

United missed ample opportunities to take the lead in the first half. Bruno Fernandes sliced a shot off target when put through on goal, while Amad also missed two presentable opportunities and forced a good save from Chelsea goalkeeper Mike Penders.

If results go against United this weekend, they could drop into the relegation zone, having began the weekend in 16th place.