Man City star Joao Cancelo has risen to become one of the world's best full-backs

As Gary Neville, on commentary duties for Sky Sports, picked out Joao Cancelo as man of the match, he must have felt a wistful feeling of what might have been.

When Neville was manager of Valencia back in 2016, he'd urged Manchester United to take a punt on this outstanding young full-back.

United weren't convinced and now here he was in the blue of Manchester City ripping his former club to shreds.

Cancelo produced one of the most complete performances by a full-back you're ever likely to see in the Premier League, underlining precisely why Pep Guardiola now trusts him in pretty much every match.

Not only did the Portuguese neuter United's limited attacking threat, he ran Aaron Wan-Bissaka ragged down the City left, setting up both of their goals in a 2-0 win that might easily have been 6-0.

United only managed 73 passes in the final third all game. Cancelo alone managed 46. Rarely, if ever, have a United team been so thoroughly outclassed in a Premier League game.

Guardiola has favoured Cancelo to Oleksandr Zinchenko at left-back for much of the season. It isn't hard to see why - the 27-year-old is arguably the best left-back in English football.

You could make a strong case for him being one of the best right-backs too. The skills are transferrable and it's Cancelo's natural position. His versatility works nicely for Guardiola.

There were times, notably during his first season at the Etihad in 2019-20, when Cancelo didn't look like a £60million player, the most expensive right-back in history.

Even last season, despite being a regular starter in both the Premier League and Europe, Guardiola went with Zinchenko at left-back in the Champions League final against Chelsea, with Cancelo an unused substitute.

But things have reversed this season. Now the Portuguese player is undroppable, fully at ease on either side of City's defence and even playing a hybrid role in midfield when required.

'He is an athletic machine, he is a brilliant runner, a beautiful runner with the ball and he is a tough kid as well,' Neville enthused after Saturday's derby.

'He is strong, he is brave in his defending, he affects the game in defence and in attack, and he is delivering what I thought he would.

'He was playing left-back and he plays equally well as a right-back. He can play midfield. He makes this City team better and that is a hard thing to do.'

Neville only managed Valencia for four months but it was enough to realise the quality of Cancelo, who was then 22.

He was his own worst critic at that time, cursing himself even after making a mistake in training.

Neville had to make Cancelo realise errors were part of football's learning curve and his innate talent would be enough to prevail.

Neville believed Cancelo was good enough for Manchester United but Louis van Gaal hadn't long signed Matteo Darmian in the right-back role and they also had Antonio Valencia so a move didn't materialise.

Their loss has proved to be City's gain, with Cancelo arriving there via a season on loan at Inter Milan and a season at Juventus, where Italian football's school of hard knocks further toughened him up.

But Cancelo was pretty tough anyway, his early life affected by tragedy.

He was 18 and sat alongside his brother Pedro, then nine, in the back seat when his mother Filomena was killed in a car accident near Lisbon in January 2013.

The two boys escaped with only minor injuries but the loss of his mother saw Cancelo, then at Benfica, almost give up on football entirely.

He stayed away from training for a month but a heart-to-heart with his father Jose saw Joao return to his club with a new-found mission to make his mother proud.

'I'm dead inside, but I'm going to be strong and I'm going to give you the greatest pride in the world,' he wrote on social media at the time.

That inspiration has taken him far. As he told ESPN Brasil earlier this year: 'As I often say, my mother saw me being born and I saw my mother pass away.

'That's why I say that each title, each achievement individually is all dedicated to my mother because, as I said, she's the woman and the person of my life.'

There have already been plenty of achievements. Cancelo won Serie A with Juventus in 2018-19 and the Premier League with City last season.

He has played 30 times for Portugal but suffered rotten luck too. He didn't make the final cut for the 2018 World Cup and was forced to withdraw from Euro 2020 after testing positive for Covid-19 two days before their first match.

But at 27, all the evidence points to a player entering their prime and Cancelo will be reluctant to give up his starting place at City even if Guardiola wants to rotate.

After all, he comes out top among City's defenders when it comes to tackles and aerial duels won, interceptions and recovering the ball this season.

Cancelo's two assists at Old Trafford came just days after he set up three goals in the Champions League win over Club Brugge.

Besides, he is unlikely to be dropped by Guardiola anytime soon because the City manager has successfully coached him into an indispensable part of his set-up.

As well as his comfort at left-back or right-back, it's Cancelo's ability to drift into midfield when City are building one of their moves, providing an extra man to overload opponents.

Time and time again, United found themselves outnumbered when City pushed forward on Saturday. Once their attack had gathered momentum, Cancelo could find space on the left and get in behind United's defence with a quick switch pass.

The results were devastating. Not only did Cancelo deliver the low cross that Eric Bailly sliced past his own goalkeeper David de Gea for the early opener, his floated pass picked out Bernardo Silva to squeeze in their second after Harry Maguire and Luke Shaw switched off.

All in a day's work for a player whose life and career has been shaped by tragedy, self-admonishment and the uncertainty of not always playing.

But now Cancelo is certainly fulfilling his promise to his mother to be the best.