Campbell made his Premier League debut in victory over Stoke City.
He told the Evening Chronicle: "It's nice to know the manager is going to give you a chance if he can.
"If he thinks you are good enough, he will. It makes you want to work harder so that he can't not play you really. It gives everybody a lift.
"Not just me, everybody in the Academy and reserves knows if they work hard enough then the manager will give you your chance and you will get in there."