Lisandro Martinez trudged off the pitch at Stamford Bridge in silence, the whistles and jeers of the Chelsea supporters following him all the way to the tunnel. Manchester United coach Jonny Evans exchanged a brief word, but Martinez appeared to pay no heed.

In the space of just 83 seconds, the Argentine defender committed two fouls that reduced Michael Carrick's side to 10 men and left them trailing 2-0 — a sequence of events that effectively ended the contest and deepened United's already alarming crisis.

What happened

Martinez was already on a booking when Estevao delivered a corner. Rather than tracking the ball, Martinez raised his elbow and caught Chelsea defender Wesley Fofana in the face at the far post. The incident slipped past the referee in real time, but VAR official James Bell directed referee Peter Bankes to the pitchside monitor, where the conclusion was straightforward.

World Cup final referee Darren Cann was unequivocal in his assessment, telling BBC Sport: "He jumped into him, making no attempt to play the ball and not even looking at the ball as it came in from the corner. Martinez was rightly sent off for two bookable offences, as well as conceding a needless penalty for the reckless challenge on Fofana."

Cann described Martinez's actions as "inexplicable" — a word that cut to the heart of the frustration felt by United supporters and coaching staff alike.

Carrick's side let down at a critical moment

It was telling that Carrick did not look in Martinez's direction as he left the pitch. The United manager was already huddled with assistant Steve Holland, searching for a way to salvage something from the match.

Speaking afterwards, Carrick declined to deliver a verdict on the incident, saying he had not yet reviewed the footage. "The second goal and losing a man at that stage had a big influence on it, for sure," he acknowledged.

Former England and Liverpool defender Stephen Warnock offered a blunt summary: "At 1-0 down United are still in a decent position — you're still in the game. At 2-0 and down to 10 men, effectively the game is over." Warnock added that Martinez was "making mistake after mistake at the moment."

Former Chelsea and England midfielder Joe Cole was equally forthright on TNT Sports. "In a Man Utd shirt, he's just at the scene of the crime too often," Cole said. "Whatever the next Man Utd phase is, I think Martinez's time at the club has run its course."

A performance that deserved better

The cruelty for Carrick is that United had been the better side for long stretches. In the first half, they were significantly more composed than in recent three-goal defeats to Como and Bournemouth. Four clear chances came and went, with Bruno Fernandes and Amad both wasting opportunities they would expect to take.

Chelsea keeper Mike Penders produced two excellent saves, and even in the closing stages, Bryan Mbeumo's powerful effort failed to find the net. Morgan Rogers ultimately broke the deadlock for Chelsea before Martinez's meltdown put the match beyond reach.

United were saved from a third consecutive three-goal defeat only by a tight VAR offside call that ruled out Estevao's effort — cold comfort at best.

Relegation fears grow

The defeat leaves United nine matches without a win in all competitions — their worst such run since 1988-89 — and on the brink of dropping into the Premier League relegation zone for the first time since Sir Alex Ferguson's early days at the club.

Martinez will now serve a suspension for next Sunday's Premier League fixture against Aston Villa at Old Trafford. Before that, United host Roma in the Champions League on Tuesday, a match Carrick knows his side must win to keep their European qualification hopes alive.

"There's no words I'm going to explain to you now that makes any difference," Carrick said. "We've got to move forward and win football matches — it's as simple as that. The way we played in the first half definitely gives encouragement, and we've got to take that."