The Spanish stopper bore the brunt of criticism from some quarters following his move to Old Trafford from Atletico Madrid in 2011, but he is now established as United's first-choice as the last line of defence.
Having shared goalkeeping duties with Anders Lindegaard throughout the first half of his maiden season in England, De Gea's increasingly assured performances saw him become one of the first names on the United team sheet. His save to deny Emanuele Giaccherini at the Stadium of Light proved to be a turning point in United's recent 2-1 win over Sunderland, and was hailed by Peter Schmeichel as "one of the best seen in the Premier League."
Still a couple of weeks short of his 23rd birthday, De Gea is now approaching 100 appearances for United, and the manager is convinced the keeper will be adding more to the Premier League title he won with the club last season.
"I think David over the years has come in here and proved himself at Manchester United," Moyes declared. "Sir Alex brought him young and played him at a time when it could be difficult to play a young goalkeeper. Goalkeeper and centre back these days are two of the hardest positions on the pitch for a young player. Manchester United doing that over the last couple of years has shown what you can get.
"He is a top goalkeeper. He will go on in time to be one of the best there is, I have no doubts about that. He's still young for a goalkeeper, people will be looking at him for the next 10 years."