De Gea kept a cleansheet in victory at Norwich City yesterday.
"Wayne (Rooney) and Robin (van Persie) score big goals and win games for us but David has won us big points as well," said Moyes.
"He is also coming and taking crosses and being brave and we want him to do that.
"I look around and he is one of five or six young players in the team who are going to be part of the next five or six years and that means he can only get better."
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