It was around this time last year the negative headlines began to emerge. After Spain’s thrilling 3-3 World Cup draw with Portugal, David de Gea’s position as La Roja's first-choice goalkeeper was scrutinised.
De Gea had gifted Portugal their second goal, having let Cristiano Ronaldo's shot slip through his grasp.
After the game, temporary Spain boss Fernando Hierro, who'd been parachuted in at the 11th-hour to salvage the nation's campaign in Russia following the extraordinary circumstances surrounding Julen Lopetegui's dismissal, defended the Manchester United No.1.
“We know that goalkeeper is a special position,” Hierro said. “With a special psychology, and we have no doubts about him at all.”
Those doubts, however, have intensified in the year that's followed. The 28-year-old's error-strewn campaign at United was hard to ignore and, while he remains the Red Devil's go-to between the sticks, he has ceded his national team spot to Chelsea‘s Kepa Arrizabalaga.
His long-term future at Old Trafford is also uncertain. Reports have emerged suggesting Paris Saint-Germain are interested in his services following Gianluigi Buffon's decision to leave the French champions.
Out of contract in 2020, there is a possibility United will allow De Gea to leave this summer as opposed to losing him for free at the end of next season.
If he goes, United will surely look for a replacement. Here, we analyse the five main candidates.
According to ESPN, Oblak wants to leave Atlético Madrid this summer after what they describe as ‘broken promises over his future'.
The 26-year-old, a four-time winner of LaLiga's Zamora Trophy, awarded to the keeper with the most clean sheets in a season, wants to play in the Premier League. United's lack of Champions League football in 2019/20 is not thought to be a deal-breaker for the Slovenian.
One of the best goalkeepers in the world, Oblak boasts a remarkable record for Atleti, with 117 shut outs in 208 appearances.
— Football Whispers (@FB_WHISPERS) June 11, 2019
In terms of a goalkeeping skill-set, he has everything; reflexes, shot-stopping abilities, quality distribution and conviction when claiming crosses into the box.
He boasts the best save success rate in each of the past two seasons in Europe's top five leagues. Many will claim he's had Spain's best defence shielding him but the Slovenian's stellar reputation has been built by a series of assured displays, not by those in front of him.
Oblak once again shone for Diego Simeone's side in 2018/19. Los Rojiblancos conceded 29 LaLiga goals against an expected 42.57, meaning he saved roughly 13.57 goals. The fact they conceded 29 against a post-shot xG of 39.8 highlights how effective their keeper has been guarding the goal. Indeed, Atleti ranked first in open-play goals to xG ratio.
Finally, in Ederson and Alisson, Manchester City and Liverpool have shown the benefits of spending big on world-class goalkeepers, so if United were to cash in on De Gea, there are few who can match the skill and experience of Oblak.
Per The Independent, it's Onana, not Oblak, who is United's preferred replacement for De Gea.
With United keen to strengthen in a number of outfield areas, Oblak's reported £100million price-tag renders his arrival in Manchester highly unlikely.
According to the report, Onana would be available for £40million. Having turned 23 in April, the Ajax stopper can't match Oblak's experience but produced a string of eye-catching saves during the Dutch club's shock run to the Champions League semi-finals.
The Cameroon international boasts razor-sharp reflexes and astute distribution skills, the latter often launching counter-attacks for Ajax.
An exciting prospect who is clearly on an upward curve, Onana would be an attractive, cheaper alternative to Oblak.
Last kick of the game…
— UEFA Champions League (@ChampionsLeague) November 15, 2018
The Independent‘s report claims United are also weighing up a possible move for Cillessen.
The 30-year-old Dutchman, Onana's predecessor at Ajax, is reportedly fed up with being the second-choice at Barcelona behind Marc-André ter Stegen.
However, despite his secondary status at the Camp Nou, Barça would still demand a hefty sum for an experienced international with two years left on his contract.
Cillessen has been used mainly as a cup keeper, helping the Catalan giants win back-to-back Copa del Reys in 2017 and 2018.
He has, however, come in for heavy criticism following the Netherlands' Nations League final defeat to Portugal. Some felt Cillessen could have done more to keep out Gonçalo Guedes's winning effort. It's unlikely such an isolated incident will decisively impact United's thinking but Cillessen's age and price-tag makes him a less attractive candidate than Oblak and Onana.
There is, of course, an argument that United have a solid De Gea replacement already at the club in Romero.
The 32-year-old, who joined from Sampdoria in 2015, has 96 caps for Argentina has often proved an able deputy on the occasions when he has stepped in for De Gea, including United's triumphant Europa League campaign in 2016/17.
An established international, Romero has always played second-fiddle to De Gea but, given he will turn 33 in February, United would perhaps be excused for favouring a keeper who will offer more years of service at a top level.
Also, Romero's red card for handling the ball outside his area in the Carabao Cup defeat to Derby County hardly bolstered his case to be United's first choice.
A second man already on the books at Old Trafford. While De Gea's reputation was taking a hit in 2018/19, Henderson's blossomed to the point where he is now considered one of England's brightest goalkeeping prospects.
The 22-year-old, who's been at United since 2011, joined Sheffield United on loan last summer having spent the 2017/18 campaign at Shrewsbury Town.
That move has worked perfectly for the youngster; he played every minute of the Blades' successful promotion campaign, helping Chris Wilder's men regain their top-flight status for the first time since 2007.
Henderson was a rock for the Bramall Lane outfit, keeping 21 clean sheets and making 113 saves in total. He also saved the only penalty he faced.
There were a couple of errors but Henderson has shown tremendous promise during his year in Sheffield.
Wilder is understandably keen to retain his services for United's Premier League return and, while sections of the Old Trafford faithful would prefer to see him given an opportunity under Ole Gunnar Solskjær, the more likely scenario will see him loaned back to the Blades for another year to test his credentials as a top-flight keeper.