David de Gea is set to become the richest goalkeeper in the world.

Although not yet official, reports suggest that De Gea will sign a new six-year contract with Manchester United. The deal is valued at £117 million, and De Gea is expected to earn £375,000 per week. The contract extension, which will be signed once the Red Devils return from their preseason tour, will make De Gea the best paid goalkeeper in world football.

If any goalkeeper deserves to make that amount of money, it’s De Gea.

The deal comes almost four years after De Gea nearly secured a well-documented move to Real Madrid. On August 31, 2015, Manchester United and Real Madrid agreed to a massive swap deal that would’ve seen the Spanish goalkeeper return to his motherland. In exchange, Los Blancos would’ve sent £29 million Manchester United’s way, along with Keylor Navas, who had only made 11 appearances for them up until that point.

Unfortunately, the deal fell through. It’s unclear why exactly — both sides have blamed the other for the failed deal — but rumours suggest that a “dodgy fax machine” was behind the mess.

Whatever the reason, the swap didn’t take place. De Gea remained at Manchester United, where he has continued to cement his place as one of the top goalkeepers in the world, while Navas went on to win three-straight UEFA Champions League titles with Real Madrid.

But what if the move went through? What if the paperwork was sent on time, and the two goalkeepers ended up trading places? How different would the futures of both goalkeepers (and both clubs) look?

Today, let’s look back at one of the most hyped transfer deals of the 21st century, and how history may have changed had it played out differently. As we’ll see, one working fax machine could flip the fortunes of not just the two clubs involved, but also for the teams around their leagues.

Manchester United

With David de Gea gone, Manchester United say goodbye to their most valuable asset. Fortunately, they don’t have to do any goalkeeper shopping because they’re getting a replacement in return.

In five seasons with Los Blancos, Keylor Navas has developed into one of Real Madrid’s top players. Renowned for his monkey-like agility and quick reflexes, Navas was an integral part of one of Real Madrid’s most successful generations. He backstopped Los Blancos to three Champions League titles in a row — the first starting goalkeeper to do so in the UCL era — and he constantly produced the big save when he needed to. He was respected by the club’s senior members, including Sergio Ramos, and he always had Zinedine Zidane’s support despite the multiple transfer rumours surrounding his job security. An argument can be made that, based off of his clinical saves in the right moments, Navas’ defensive impact was equal to the offensive impacts of Luka Modrić & even Cristiano Ronaldo.

But hindsight is 20/20, so we have to look at this from a 2015 perspective. Navas, who was 28-years-old at the time of the switch, was not the giant that he is viewed as today. Sure, he was just a year removed from a stupendous 2014 World Cup that saw him earn plaudits worldwide, and he did become the first goalkeeper to win Player of the Year at the 2014 CONCACAF Awards. But aside from a career year in 2014, there wasn’t much to suggest that Navas would cut it as an elite-level goalkeeper.

Granted, Navas did post a career season prior to the 2014 World Cup. In the 2013-14 season, he made a La Liga-best 267 saves (an average of 7.4 saves per game), conceded the fourth-lowest goals in the league with 39 goals conceded, and was nominated for the league’s best goalkeeper award alongside Atletico Madrid’s Thibaut Courtois and Malaga’s WIlly Caballero. Given that he was playing for Levante, one of the lowest scoring clubs in La Liga that season, those numbers are, frankly, bonkers.

But it must be remembered that the 2013-14 season was Navas’ first season as a starting goalkeeper in a top European league. He had spent the previous two seasons backing up Gustavo Munúa, and he played in the Segunda Division in the 2010-11 season following two seasons in Costa Rica. At the time of the swap deal, Navas had played just 53 games in a top European league, a very minuscule number for a four-season veteran.

As prodigious of a season as Navas’ 2013-14 campaign was, would it be enough to convince Manchester United that he was anything more than a one-season wonder?

With Navas replacing De Gea, I think Sergio Romero would’ve been fancying his chances at the number one position. The Argentine goalkeeper joined Manchester United on a three-year contract a month before the swap deal, and with De Gea’s departure looking eminent, he was likely brought in to replace the Spaniard. This is why Romero started in Manchester United’s first six games of the 2015-16 season, including four Premier League matches.

Would Romero have continued as the club’s number one goalkeeper even with Navas joining the club? Maybe. The only reason why Romero didn’t continue as United’s starting goalkeeper was due to De Gea’s failed transfer. With De Gea being one of the top goalkeepers in the world, it’s difficult to imagine Romero continuing as the club’s starting ‘keeper if De Gea returns. But if Navas — a goalkeeper who at that point only had one season as a European first division starter under his belt — comes in place of De Gea, Romero likely continues starting matches.

For all of the focus I’m putting on Navas’ lack of appearances up until that point, it’s not as though Romero has done much better. After back-to-back seasons of 30+ appearances with Sampdoria, Romero found himself on the bench between 2013 and 2015. He made zero appearances in 2013-14, and only played in 10 matches the season after. He was released by Sampdoria at the conclusion of the 2014-15 season, and he only signed the deal with United after nearly two months of being a free agent.

Realistically, I think both goalkeepers would split playing minutes in their first season together. Louis van Gaal signed Romero for the purpose of taking over number one duties if De Gea departs, but he would’ve been familiar with the quality of Navas given their meeting in the 2014 World Cup. I believe Van Gaal would’ve given each ‘keeper a fair shot at proving their worth.

It’s anyone’s guess what happens after the 2015-16 season, though. In our timeline, Van Gaal was sacked at the campaign’s conclusion, and I’m not certain if much would’ve changed in an alternate reality. Does Van Gaal end up staying for another season? Does Jose Mourinho still replace him? Where does Ole Gunnar Solskjær fit in to all of this, if he fits in at all? Your guess is as good as mines.

I can’t speculate with certainty what happens to Navas and Romero after their debut season together either, due to the multiple potential outcomes. If Navas shines like he did post-Casillas, he likely takes the United number one role. But would Romero be fine with that? And vice-versa.

Furthermore, if one of the two goalkeepers decides to leave, where does he go? Different offseasons bring up different possibilities, although I’m sure each goalkeeper would have their own preference.

For Romero, given the uncertainty surrounding his club future not long ago, I wouldn’t be surprised if he sees out his United contract until the end. If he does depart, maybe he’d return to his native Argentina; he was linked to Boca Juniors and River Plate as early as 2017.

As for Navas, if he were to leave to another European club, I believe he’d prefer to return to Spain. Maybe Valencia following Diego Alves’ departure in 2017? Or maybe Sevilla in 2018, following Sergio Rico’s loan to Fulham and David Soria’s transfer to Getafe? I can’t say for certain, though.

Real Madrid

Theoretically, David de Gea would’ve been the perfect replacement to the departing club icon Iker Casillas, what with him arguably being the best goalkeeper in the world at the time. De Gea was coming off of a 2014-15 season in which he posted a save percentage of 72%, one of the highest among Premier League goalkeepers with over 3000 logged minutes. His league heroics also saw him take home Manchester United’s Sir Matt Busby Player of the Year award and the goalkeeper spot in the PFA’s Team of the Year.

From an advertising standpoint, De Gea would’ve been more marketable than Keylor Navas. His connection to Madrid would’ve made him a hit with the locals, even if he started his career with Atletico Madrid. Him being the next in line for the Spanish number one spot adds another spin to the “De Gea is Casillas’ heir” storyline, and I wouldn’t have been surprised if Real Madrid ran with that in subsequent advertising campaigns. De Gea’s experience in English and European competitions had already garnered him a substantial following abroad, so his move to Madrid would’ve attracted non-Spanish attention.

Of course, none of this guarantees success. While the odds lean more in favour of De Gea succeeding with Real Madrid than not, it’s all down to speculation. We can only theorize if De Gea would’ve made the same saves and delivered the same performances that Navas did en route to Madrid’s back-to-back-to-back Champions League titles between 2016 and 2018, or their league championship in the 2016-17 season.

Supposing it did lead to more success, the future of Rafael Benítez at Real Madrid might’ve looked slightly different. At the time of De Gea’s move, Benítez would’ve been just two months into his three-year contract as Real Madrid’s head coach. Benítez didn’t last anywhere near as long, due in large part to Real Madrid being outside of the top two in January 2016. The club were two points away from second place and four points away from first, so one or two different results in the league would’ve made a difference. If De Gea was there to help flip a negative result into a positive, maybe Benítez would’ve been around for longer.

This also impacts Zinedine Zidane’s place in history. The former footballer took over following Benítez’s dismissal, and he instantly returned the club to European glory. His initial two-and-a-half seasons in charge post-Benítez saw Madrid clinch three Champions League titles in a row, beating the likes of Atletico Madrid, Juventus, and Liverpool in the finals. But if Benítez remains, Zidane probably stays with the Castilla team’s coaching staff, and with that, the team’s trophy haul likely fluctuates. I still believe Zidane would eventually be promoted to the senior team’s head coaching role, but it would probably happen later rather than sooner.

Credit where credit is due, Keylor Navas was one of Real Madrid’s best players during the 2015-16 season, and it’s hard to believe that any other goalkeeper, even one as good as De Gea, would’ve bested his numbers.

The season following the failed swap deal, Navas appeared in 45 matches across La Liga and the Champions League. He made 121 total saves; an average of roughly 2.7 saves per game. 48 of those saves came in the Benítez era; an average of 2.4 saves per appearance. This includes a penalty save vs. Griezmann in November 2015’s edition of the Madrid Derby (a 1-1 draw). It was just one of multiple big, game-deciding saves Navas made that season, but it wouldn’t have happened had the De Gea-Navas swap deal went through.

With Navas gone, Kiko Casilla, who joined Real Madrid from Espanyol earlier that summer, backs De Gea instead of the Costa Rican. Casilla did appear in a fair amount of games for Real Madrid from 2015 to 2018, including 25 matches in La Liga. However, a number of these appearances were due to Navas being out injured or were made in the Copa del Rey, so if De Gea stays healthy, Casilla’s minutes probably drop. He might make as many appearances in the Copa del Rey, given Madrid’s tendency to play their second goalkeeper in that competition, although it’s not a given.

Now, does a De Gea move impact Casilla’s 2019 transfer to Leeds United? Possibly. One of the leading factors behind Casilla’s move is the fact that he was demoted to Real Madrid’s third goalkeeper spot for the 2018-19 season due to Thibaut Courtois’ arrival in 2018. But with De Gea as Madrid’s number one, the purchase of Courtois never would’ve happened, so Casilla would remain as De Gea’s back-up going into the 2018-19. As a result, maybe Casilla decides that he would like to remain with Los Blancos.

Regarding how long De Gea would’ve remained with Real Madrid, I doubt he would’ve signed for a contract length of less than four years. Los Blancos would’ve wanted to lock him down for long time, and given De Gea’s want to move to Madrid, I’d expect him to sign long-term. Given that De Gea signed a four-year deal (with an option for a fifth year) with Manchester United during the 2015-16 season, I don’t see why he wouldn’t sign for a similar, if not longer, length with Real Madrid.

Other clubs

Manchester United and Real Madrid wouldn’t be the only major clubs whose futures would be impacted by a David de Gea-Keylor Navas swap. Chelsea’s goalkeeping future would also look pretty different.

There’s the case of Thibaut Courtois. The Belgian goalkeeper joined Real Madrid last summer for a fee of around £35 million. He signed a six-year contract with Los Blancos, and while he only played 35 games last season, Courtois will likely be Madrid’s long-term starter until his contract runs out in 2024.

But if De Gea joined Real Madrid in 2015, Courtois would likely still be at Chelsea. If De Gea was performing up to his elite standards, there would be no reason for Los Blancos to purchase Courtois (or any other goalkeeper). Therefore, it’s likely Courtois would’ve remained a Chelsea player.

Or maybe not. Sure, he has a six-year deal to fall back on now, but Courtois’ Chelsea future was not as secure, even with Real Madrid out of the picture. Courtois had just one year remaining on his Chelsea contract prior to joining Real Madrid. His old Chelsea deal would’ve expired this very month if it went the distance.

This opens up a whole new can of worms regarding Courtois’ future, the most important of which being if Chelsea would re-sign him. Given their current transfer ban, which prevents Chelsea from buying or borrowing players or signing free agents, they’d really have no choice but to do everything they can to re-sign Courtois. If Courtois leaves, Chelsea would be forced to play through an entire season with Willy Caballero as their number one goalkeeper (no Kepa Arrizabalaga, more on him in a bit). For a club that views itself as a legitimate league contender, is going an entire season with an inconsistent, error-prone, soon-to-be 38-year-old goalkeeper really the way to go? Is that really the risk the club would want to take? I doubt it.

But suppose Courtois sees out his deal, rejects all contract extensions put forward by Chelsea, and goes into free agency. Where does he end up then? Looking at the current market, there’s a scarcity of world-class teams who need a top-class goalkeeper. Given their interest in De Gea, I’d imagine that Paris Saint-Germain would be the front-runners to sign Courtois in this alternate universe. It’s also possible that AS Roma, who would’ve been looking for a new number one following Robin Olsen’s failed debut season, and Tottenham, a club criticized for fielding Hugo Lloris as their starting goalkeeper, would’ve thrown their hats into the ring too.

Another goalkeeper who would be impacted by De Gea’s move to Real Madrid is Kepa Arrizabalaga. Obviously, Courtois not moving to Madrid would mean that Kepa doesn’t join Chelsea in 2018. No move means no €80 million fee, which means the title of the most expensive goalkeeper in history would belong to Liverpool’s Alisson Becker.

The impact of De Gea’s move on Kepa extends beyond a simple transfer record, though. In fact, this one switch, had it happened, would’ve completely changed Kepa’s buyout fee. Initially, Kepa Arrizabalaga was signed to a deal with a €20 million release clause. He was in the middle of the final year of that deal. But when Real Madrid ‘s interest in him peaked midway through the 2017-18 season, Athletic Bilbao quickly moved to protect their asset. They signed the young goalkeeper to a new seven-and-a-half-year deal and tagged him with an €80 million release clause. Real Madrid backed off as a result, but Chelsea paid the price a few months later.

Had De Gea joined Real Madrid in 2015 though, there likely wouldn’t have been any reason for Los Blancos to court Kepa. And if Real Madrid’s interest is removed, so too is Kepa’s €80 million price tag.

That doesn’t mean that Athletic Bilbao would’ve just sat idle. After all, Kepa was in the final year of his initial contract, and I don’t think Bilbao would’ve allowed him to go into free agency. Given his performances that season, which included a nine-save effort in a 1-1 draw with Real Madrid, I doubt Athletic Bilbao would’ve let Kepa’s contract expire without signing him to a new one. I also doubt that they wouldn’t increase his buyout fee; €20 million is too cheap for a goalkeeper who turned a lot of heads on an otherwise disappointing 2017-18 Athletic Bilbao team. Do Bilbao put an €80 million price tag on him, though? Without Real Madrid’s persistent interest, I don’t think so.

Going back to the Premier League, Newcastle United might also be impacted by a De Gea move due to the obscurity surrounding how long Rafael Benítez lasts at Real Madrid. If Benítez stays at the club for, let’s say, a full season, what’s the likelihood that he joins Newcastle United then? After all, the club were relegated following the conclusion of the 2016-17 season, and that was with Benítez at the helm for the final few games. If Benítez finds himself out of a job during the summer of 2016, would he relegate himself to the Championship to coach Newcastle? And if he doesn’t, do Newcastle return to the Premier League as quickly as they did?

What do you think would’ve happened had David de Gea and Keylor Navas swapped clubs in 2015? Let me know your speculations in the comments and on Twitter.