City claimed that the move was purely motivated by money, while fans on the other side of town argued that their team had plenty more to offer than just money, with a manager who wins silverware for fun, puts trophies in the bag most seasons and boasts a status in world football that all but Real Madrid would struggle to match.

The truth of the matter is somewhere between the two, though Sanchez's connection to United goes back longer than some might have thought.

"Since I was a young lad, I've always said that my dream was to play for Manchester United," Sanchez said in his first interview. "I always said as a kid that I'd like to play for United, and I once spoke to Sir Alex Ferguson about it. We chatted for around 20 minutes. And I told him that my dream was to come here to Manchester United."

While it's common for players to talk about it being a dream come true to sign for their new club, there is some evidence to support Sanchez's claim.

During the 2010 World Cup, one of his international teammates claimed that the only club he talked about was United, while pictures of Sanchez wearing a jacket with a United badge on from years before he moved to the Premier League did the rounds of social media after his transfer was confirmed. Conversations over Sanchez's motivation to choose United will continue to rumble on, among rival supporters at least, but United fans can now turn their attention to watching one of the league's most talented players line up for their team.

Sanchez will likely make his debut at Wembley against Tottenham Hotspur, where he can expect a less than warm welcome due to his Arsenal affiliation, and Jose Mourinho will have to decide the best place to play him.

Romelu Lukaku starts up front and is usually supported by one of Marcus Rashford or Anthony Martial on the left, Jesse Lingard behind him and Juan Mata on the right. Henrikh Mkhitaryan, who departed for the Emirates as part of the Sanchez deal, was interchangeable with some of these players but fell out of favour some time ago. The most obvious player to lose their place in the starting team is Mata on the right, a position in which Sanchez could thrive, though this isn't the first time we've heard the Spain international's future at the club written off.

When Mourinho was appointed 20 months ago, the popular opinion was that Mata would be the first player sold. Having been named Chelsea's player of the year for two consecutive seasons, Mourinho moved him on to United a matter of months after coming back to Stamford Bridge for his second stint.

In Mourinho's first game in charge at United, the Community Shield victory over Leicester, Mata was a second-half substitute but was taken off right at the end as the manager sought to bring on some height to wrap up the win.

"You don't do that unless you are trying to send a message," Danny Murphy said in his role as pundit for the BBC. "He is basically saying to him you are not important, and he has done it publicly. I can't see him still being at the club at the end of August."

Mata went on to play in 42 games for United the season, with only five players finishing the campaign with more appearances than him.

"When I came here people thought Mata was in trouble, but I knew he wouldn't be in trouble," Mourinho said last year. Mata has adjusted to play in the way that Mourinho wants him to and has made a positive impact on the team as a result.

Yet the 29-year-old, who turns 30 in a few months' time, is the player most at risk to lose out to the Chile star. Despite reports at the start of year claiming that the clause for a further year in his contract would be activated, there has been no confirmation yet, which means Mata could leave for free at the end of the season.

In terms of goals and assists, Mata is lagging behind the other forwards with Martial, Rashford and Lingard all registering more than him. However, when comparing their average contribution over 90 minutes, Mata far exceeds the competition with completed passes, key passes and chances created. Yet that won't put him above Sanchez in the pecking order.

Mata's signing was the last from a rival club that had United fans in awe, hardly able to believe their eyes when footage emerged of him getting off the helicopter in Carrington. It's fitting then that Sanchez, the latest transfer to leave United supporters gobsmacked, should be the one to replace Mata in the team.

The Spain international could still play a role at United, but with his playing time likely to be more limited, he might wonder whether it's worth sticking around.

United supporters would be sad to see him go, but the sight of Sanchez in their no. 7 shirt will likely ease their pain.