The latest setback was last night. Spain's shaky victory over Romania. A triumph earned in no small way to the La Roja man between the posts. Only it wasn't the United keeper. De Gea had to make do with a place on the bench. No, the player being celebrated today in Spain is Kepa Arrizabalaga, of Chelsea. From the same competition. From a club of similar level. There can be no accusations of bias leveled at Spain coach Robert Moreno. He simply went with what he thought best for the game - and was rewarded with a five-star performance. The local press and media unanimous: in Kepa Spain have their new No1.
Indeed, those inside Moreno's extended backroom are now saying there's no guarantee of De Gea making the bench in the future. Pau Lopez, Tottenham's former third stringer and now AS Roma's outright No1, impressing coaching staff this week. Moreno making it clear as the players assembled for this international round that he regarded all three keepers as his potential No1. And as was shown last night, these were no empty words.
So what's happened? How has De Gea's crowned slipped? Well, again from inside Moreno's camp, it has come down to personality. Kepa is a bigger character than De Gea. Louder. And it's something Moreno appreciates in his goalkeepers. Where predecessor Luis Enrique refused to budge - always supporting De Gea, even during and after his disastrous World Cup in Russia, his assistant did have his doubts.
Indeed at the end of last season, when Kepa was selected ahead of De Gea for the Euros qualifier with Sweden, it was Moreno, not Enrique who gave the most robust reasoning for the choice. His Spain teammates may've been impressed by De Gea's face being the first they saw upon their gathering at the Ciudad del Fútbol - but that wasn't enough to win Moreno around.
And that's just it. De Gea has been trying to snap this slump. To break out of this funk. Always one for introspection. To consider where and how he can do better. Near the end of last season, De Gea gathered his trusted support team, including his father and United coach Emilio Alvarez, to look at every aspect of his game. The faults. The lapses. It was no holds barred. The Spaniard recognised something was wrong - and was determined to fix it. Even once the season was over, De Gea skipped his summer break and instead sought permission from the RFEF to use their facilities at the Ciudad del Fútbol. A coach and gym manager were even brought in to help De Gea during the near fortnight.
So he has been trying, has De Gea. But it just hasn't been falling his way. His name no longer mentioned among the elite of the game. Not by the media - and crucially not by his peers. Indeed, given the opinion of Moreno, he's not even regarded as the best Spain has. But as we say, this hasn't been from a want of trying.
So something has to give. And Ole Gunnar Solskjaer has be across it. The United manager doesn't want to lose his No1. Unlike those before him - Jose Mourinho and Louis van Gaal - Solskjaer took the job wanting to work with De Gea. The thought of replacing the Spaniard has never crossed his mind.
But something has to change for De Gea. Whether it be as a United player, or elsewhere, he needs something new. Solskjaer has added Richard Hartis to his staff this season to work alongside Alvarez. A new voice. A fresh set of eyes. It could make the difference.
The one constant in Kepa's career these past three seasons has been change. In his final season with Athletic Bilbao, he saw Aitor Iru replaced by Imanol Etxeberria, before moving to Chelsea, where again Italian keeper coach Massimo Nenci was replaced by Henrique Hilario this season. For all that upheaval, no-one can argue it's worked against the 24 year-old's development.
With De Gea's contract running down and that new £350,000-a-week offer remaining unsigned, Hartis could be the last roll of the dice for United. But he was primarily hired as a development coach. His expertise is bringing through youth players.
De Gea is in a slump. There's no doubt about it. And he's struggling to break out of it. After eight years of progress with the club, De Gea's career has hit a brick wall.
Whether it be luck or a new destination, United's No1 needs a change to get his game back on the rails.