They returned with a humbling 4-0 loss and the stark realisation of how much they still had to improve to match the Spanish kings.
For the centre-back it was a particularly sobering moment as Lionel Messi – who scored a hat-trick – Luis Suarez and Neymar left his defence dazed in defeat.
While under-fire keeper Claudio Bravo was sent off against his former club, Stones was also criticised as he too endured a difficult debut campaign following a £47.5 million move from Everton in the summer.
But Pep Guardiola had faith and Stones had no fear, working hard to rebuild a reputation that had seen him lauded as a future defensive great.
With 11 clean sheets in 16 games this season, two of them with England, the 23-year-old has been a commanding and classy figure as City have started unbeaten and visit West Brom in the Premier League today on the back of a club record 12-match winning run and five-point lead at the top.
He will also relish the chance to show how much he has grown in 12 months when he faces Neymar, the world’s most expensive player following his £200m summer move from Barca to Paris Saint-Germain, again next month as England host Brazil in a Wembley friendly.
“It will be a different scenario against Brazil,” says Stones. “Playing for England, a different team, and he’s with Brazil not Barcelona this time, it will be different, but it’s another challenge.
“He’s one of the best I have faced. But there’s no fear. It’s a platform to go show yourself. When you are playing against the top names everyone wants to be the best they can and you have to prove yourself against the best.
“We were all a bit shocked of how much the transfer fee was [when he went to PSG], but it was not down to him. When I got bought I said it was the two teams who make the price and you can’t do much about it. Neymar is a top-quality player and that’s why he’s moved there. It’s always a challenge, but I look forward to it.”
After his early struggles, Stones is now showing his quality and earning deserved plaudits alongside Nicolas Otamendi, with injured captain Vincent Kompany not expected back for around another month with a muscle problem.
While likened in style to his idol Rio Ferdinand, the 23-year-old had earned the nickname the ‘Barnsley Beckenbauer’ for his control and confidence on the ball and ability to instigate attacks or sweep up behind him.
But he is determined to make his own name in the game and create his own history.
“It’s definitely flattering to have that kind of comparison,” he said of the reference to the German legend Beckenbauer. “I had heard about him. But I still have a lot to learn and achieve and I want to make my own name, make my own mark.
“I am trying to concentrate on my game, trying to keep things as simple as possible, but I watch any big games that are on and learn.
“It (the praise) pleases me. I am working hard and all I can do is keep trying and playing the way I know how. Having the team-mates around me to do that is always massive. I am learning off them too.
“For me, I think the same mentality is there as last season and the same hunger and desire to do it.
“It’s just down to hard work on the pitch and my clean sheets are speaking for themselves. As a player I am always looking to improve and the team and the gaffer is pushing us to do it.
“I didn’t feel any pressure last season because of the price tag. I think a lot of things get overseen by a few results and you get judged by that. That sticks in people’s minds. But if everyone looks back at the games and sees how I defended, how I wanted to play, they would change their opinion.
“Things are just clicking now. We are improving as a back four and the whole team is improving too.
“We brought new players in, had more time together which always helps. It has just all gelled together.”
It certainly has, with City’s mean machine at the back complemented by a goal machine in attack as they have scored 41 times in all competitions and Sergio Aguero needs one more to become the club’s all-time leading scorer.
While they may look unstoppable, Stones says City – also top of their Champions League group and in the League Cup quarter-finals – are prepared for more tough tests as they bid to grow and become English football’s major force.
“With this group, hopefully we can dominate for the next few years,” he added. “We have to take each game as it comes though, from the Premier League, Champions League and the cups, every game is a new challenge.
“Every team has got their qualities and every one we face is another challenge. But we want those challenges and are ready for them.
“Our mindset is to go out there and play our game. We do our research and it’s about executing our game plan, sticking to what we can do and believe in. It’s all about how we work as a team.”
Premier League gameweek 10 is upon us!
Here, we look at three key player battles that could go a long way to deciding where the game will be won and lost.
Who do you think will win at Old Trafford?
ANTONIO VALENCIA V DELE ALLI
The Colombian full-back has well and truly answered United’s calling for a first-class right-back and is an indispensable figure in Jose Mourinho’s side.
Valencia’s pace, agility and ability to push forward and defend well should make for an intriguing tussle with Alli, who likes to drift and create from the left-hand side.
After a stop-start beginning to his season, the England international turned on the afterburners against Liverpool last time out and looks to be getting close to his best level.
He also netted in the surprise midweek Carabao Cup defeat to West Ham. Whoever comes out on top here could go a long way to deciding which team wins this one.
ANDER HERRERA V ERIC DIER
In the absence of the injured Marouane Fellaini, Spaniard Herrera has come into his own in midfield and apparently settled his issues off-the-pitch with Jose Mourinho.
The central midfielder’s work-rate and willingness to do the dirty work, as well as get forward and support United’s forward players, will be crucial to the hosts.
But the diminutive former Athletic Bilbao star will need to get the better of north London enforcer Eric Dier, who will again have the job of steering Spurs’ engine room.
Both players are more than capable of making their mark in Manchester on Saturday, but Herrera has the edge given he has more attacking stars around him and Spurs are without a certain injured Harry Kane.
ROMELU LUKAKU V TOBY ALDERWEIRELD
This should be a pulsating contest and expect Alderweireld to channel the defensive disappointment he felt from conceding three goals to a beleaguered West Ham outfit on Wednesday, into producing a rock solid display at Old Trafford.
Apart from that blip earlier in the week, the Belgian has been vital for a Spurs side that have only shipped six Premier League goals all campaign.
While marshalling compatriot Lukaku may well be his toughest assignment in 10 matches so far, he will be buoyed by the fact the 24-year-old has failed to score in his previous two league matches and lost some of that early season zip.
These two know each other well and I fancy Alderweireld to make sure the former Everton striker is in for a tough afternoon.
If Premier League managers floated on the stock exchange then only the bravest of traders would wade into that market.
They say every army is just three meals away from mutiny and it doesn’t take much more than three defeats on the bounce for a club to stick a fork in their latest manager.
A few weeks ago Ronald Koeman was the innovator leading Everton on to a bold new era. Now he’s tidying up his CV. The fairly unmemorable Claude Puel, just about still remembered for his fairly unmemorable Southampton team, is suddenly back in the fold with Leicester.
But it’s not just their short shelf lives. The Premier League’s incumbent managers blow hot and cold in the face of public opinion from week to week, even those whose hotseats are a little cooler than most.
Think back to August – how long ago that seems now – when Mauricio Pochettino could not buy a win at Wembley, and when it was easy to sell the idea that in his second season Jose Mourinho, as is his way, would bring home the big trophies for Manchester United.
Now? Well, just think of it like a seismograph, the equipment used for measuring earthquakes – in an instant the spikes have lurched to the other extreme.
Suddenly Mourinho the pragmatist is Mourinho the philistine who refuses to change his ways, an old argument that intensifies after a couple of poor results. They need someone new … like Pochettino.
United have gone in every other direction post-Fergie, after all. First you had the tried-and-tested Brit who deserved his shot, then the quirky Dutch connoisseur of tactics, the current ‘born winner’ – it’s time to go all-in on the next big thing in Poch.
Or so one narrative goes. But if you handed the smart investor a few dirhams to dabble in our fantasy managerial stocks, they would surely plough a fair portion of their kitty into Mourinho.
Manchester City are magic. He can feel both Tottenham and Chelsea breathing down his neck. His team somehow made Liverpool’s defence look as impenetrable as the Hoover Dam. Top it off with Huddersfield summoning the spirit of 1971, and there’s been a fire sale on those Mourinho shares.
The thing is, for however regressive and intractable Mourinho’s tactics and philosophy may seem, he nearly always delivers for his stakeholders. It doesn’t matter what you see on the pitch – it’s all a mirage. Just look at that trophy cabinet, bulging with 24 trophies collected from 17 years of management. With Porto, Chelsea (in two stints), Inter Milan and Real Madrid, he has won the league title.
🔴 Man Utd
🏟 Old Trafford
— Tottenham Hotspur (@SpursOfficial) October 27, 2017
Contrast that with Pochettino, who for however progressive and flexible his tactics and philosophy may seem, has not won a trophy. Not one in eight years as a head coach.
The obvious counterpoint to that is he has not been fortunate enough to manage your Reals and your Inters, but he’s into his fourth year with Spurs now and a League Cup finalist’s medal is his only physical evidence of moderate success.
Which is why it was strange that some have claimed that Pochettino will be relieved that Tottenham were dumped out of the EFL Cup by West Ham in midweek, all the while saying that a victory would resurrect Slaven Bilic and the Hammers.
Dele Alli and Eric Dier, supposed cornerstone of this new generation at Spurs, played the entire game and should be desperate for their first cup success. It would be a huge worry if they weren’t.
And this is the problem with Spurs at the moment, which goes far beyond whether they can beat United without Harry Kane. Whereas Mourinho is a proven commodity, when you invest in Pochettino and his players, you invest in potential. It’s about time we see some returns.