The £19 million man came in for heavy flak during his debut campaign at Old Trafford. Some of it was deserved, some of wasn't.
He certainly looked flimsy in the face of the bigger, more physical sides in the Premier League, while looking tentative dealing with crosses and corners.
But his potential was evident—potential that came into blossom last season.
Named to the PFA Premier League Team of the Year, De Gea was a shot-stopping force for Sir Alex Ferguson's side.
He discovered a new-found confidence and consistency between the sticks, impressing both domestically and in key Champions League clashes with Real Madrid.
The Spaniard also put in gritty performances against the likes of Stoke City and West Ham.
Anyone who witnessed Andy Carroll's flying headbutt assault on De Gea could only offer the keeper praise for the way in which he quickly shrugged off the challenge.
But De Gea is not the finished article yet. He is close to being considered a world-class goalkeeper, but still a few yards off.
Here are some minor improvements he needs to make to become one of the best in the business:
A Vocal Presence
This one come down to adapting to life in Britain rather than anything that can be achieved on the training ground.
De Gea did not speak much English when he made the move from Atletico Madrid in 2011. He has since steadily improved his grasp of the language but is not yet proficient.
It shows during games. The likes of Rio Ferdinand and Nemanja Vidic run things in the United penalty box, not the keeper.
The Spaniard's predecessor, Edwin van der Sar, commanded more respect than any of his peers. Club legend Peter Schmeichel did, too. When the Dane barked instructions at his players, they listened.
Yes, it takes a man with plenty of backbone to order around his teammates, but I believe De Gea's hesitancy comes from the language barrier.
His command of his own penalty area will improve as he continues to settle in at Old Trafford.
Though he shows plenty of improvement in this area last term, De Gea has still yet to look 100 percent confident in dealing with set pieces.
It is perhaps a hesitancy to come off his line that is at the root of the problem.
Again, it comes down to a mastery of his own penalty area and backing himself to make the right decision.
He is no longer fumbling crosses at the same rate as in his first season—far from it—but he is still a little tentative.
Former goalkeeping coach Eric Steele did fine work improving De Gea in this area, now it is up to U.S. men's national team goalkeeping coach Chris Woods to take the 22-year-old to the next level.
The man with lightening-quick reflexes could also stand to put on a few more pounds of muscle, too.
As previously mentioned, De Gea withstood plenty of physical play last season and must be commended for his bravery.
But if he bulks up further, the likes of Carroll will not be so ready to knock him around.
David Moyes is the perfect manager to aid this transformation. The former Everton boss is known for his strict training regimes and demanding physical superiority from his players.
It is as much about being an imposing presence in the box. This was perhaps the characteristic which marked Schmeichel out from his rivals.
Who better for De Gea to model himself on?