ANALYSIS: Michael Carrick was heading to the Manchester United exit at half-time against Roma, but managed to inspire a stunning comeback reminiscent of the club's glory days

Michael Carrick must have wondered whether this was the end of his dream job.

Going into the Old Trafford dressing room at half-time, Manchester United were 2-0 down to Roma and staring at the fourth straight damaging defeat and a 10th without a win. With an international break looming and his superiors courting replacements, it was now or never.

Alan Shearer summed up the mood concisely on Amazon Prime. "There's not been anything in this performance. I haven't seen a tackle, a cross, an effort at goal. There is nothing in this performance to be positive about," he said.

"I don't know where [Carrick] starts because they have been that poor in every department. Defensively all over the place, midfield no creativity, and up front no running in behind, no efforts at goal, no holding the ball up. It's really been embarrassing for them."

Shearer's wording was reminiscent of David Moyes' infamous line in a press conference, which became a viral tweet from the club's official account: "David Moyes says #mufc must improve in a number of areas, including passing, creating chances and defending."

What happened next was reminiscent of the best nights Old Trafford has ever seen: Bruno Fernandes' retaken penalty and a brace from Matheus Cunha seeing United roar back to win. But how did Carrick do it? With two key decisions, a rousing half-time team talk, buy-in from the players and a slice of luck.

Rallying the troops

Carrick played for years under Sir Alex Ferguson and remains in regular contact with the legendary United boss, but it seems unlikely that he would have employed the hair dryer treatment. The 45-year-old is a much more reserved character. Whatever he said had the desired impact.

"I think Michael Carrick deserves a lot of credit as well, because if you were in his shoes you are thinking how can I change this around, so whatever he said to the team at half-time that got them on the front-foot and got that belief in them that they could win the game," Wayne Rooney said on Amazon Prime. "You felt it, you could feel that they could win the game, everyone was together."

It seems as though Carrick drew on the history of Old Trafford to inspire belief. "I spoke at half-time about being positive," Carrick told UEFA. "Anything can happen here, I've seen it many times over the years. You just need something to go our way and the boys were fantastic second half."

Kobbie Mainoo told Amazon Prime: "We needed a bit of a kick. We were a bit reactionary. When we lost the ball, we weren't reacting as quickly as we could have and the boss really drilled it into us that we need to be more active and take the game ourselves."

Tactical tweak

United started the game in their typical 4-2-3-1 formation, with Cunha on the left and Fernandes in the No.10 role behind Bryan Mbeumo. It is a tried and tested line-up, but it was falling flat, with a frustrated Fernandes drifting all over in search of the ball and Cunha, who is no natural winger, not holding his width.

Carrick knew it needed changing. "We put him (Cunha) inside," he explained post-match. "We swapped him with Bryan at half-time to try and get him in the middle of the pitch, try and give us a little bit of different shape, and put him in the centre of the pitch, and he found himself in good positions.”

Like the vast majority of his team-mates, Cunha has not been at his best this season; he had just two goals in 13 games before Tuesday night. But the Brazilian's passion and will to win came to the fore and the switch paid dividends.

It was Cunha who won the penalty after bursting into the box. And while his first goal owed much to inexplicable air-kick from Leonardo Balerdi, his cool finish was admirable. His ability to find space from a dangerous central position was key to the winning goal, too, as he ghosted in, took a perfect first touch and blasted in at the near post.

Carrick's tactical tweak worked nicely, but it may have been the psychological aspect that really made the difference for Cunha. "To be part of this is a heavy responsibility," he told CBS Sports Golazo. "I always talk about this, to be this guy who has responsibility in the hard moments and the good moments, to be always there to show."

Trusting in youth

One of the reasons the United fans have stuck by Carrick during this miserable start to the season is his connection to the club and its traditions. One of the cornerstones of the United of old was the pathway from the academy to the first team. Shea Lacey's impact therefore made things even sweeter.

The 19-year-old was summoned from the bench in the 75th minute to replace Amad Diallo and played the pass of the night to send Cunha through for the decisive third goal. "He's got that little glint in his eye, he plays with a bit of mischief," was how Carrick described the diminutive forward. "I think he gave everybody a bit of a lift coming on the pitch."

A cynic may argue that United's lack of depth leaves Carrick with very few other options, yet his trust in youth is still to be admired. With his job on the line, the United boss turned to Lacey - a youngster making just his 10th first-team appearance for the club - and he delivered with his first senior assist.

Things may still unravel, with Aston Villa visiting Old Trafford on Sunday before the international break when his fate will be decided. But with Jason Wilcox and Omar Berrada watching on, Carrick's decisions at half-time may have bought himself more time.