Pools cruised to a 5-0 win over Bradford City on Tuesday evening in the first round of the Johnstone's Paint Trophy.
Cooper has said that while his players feel positive after the result, they must do the basics right against Wycombe.
"You see a different atmosphere back in training after a win like Tuesday – they generally feel good about themselves," he told Hartlepool's official website.
"It's our job to keep that going because confidence is a massive thing in football and hopefully it's given us the boost to push on now. We have to be wary because Wycombe will be tough opposition because they'll be feeling good about themselves after a run of good results too.
"What we have to do is make sure we do the hard work, the cornerstones of any football match – and then hopefully that will allow us to go and express ourselves like we did on Tuesday night."
Hartlepool are yet to win a match in League Two this season.