At the start of the season, De Gea was rotated with Anders Lindegaard but Sir Alex now appears to have settled with his Spanish stopper, who has started the last eight games.
The 22-year-old told MUTV: "For a goalkeeper it's always important to have consistency and to be playing regularly; it's good for confidence and morale.
"I'm happy with my current form and I just need to keep working hard in training and hope that form continues.
"From the moment I signed I considered myself the first-choice keeper at the club but it's down to the manager; he rotates us when he feels it's good for the team.
"But obviously I've played a few on the bounce now and that's positive."