Murphy had hinted that early-round exits for Trump at the start of the season were due to complacency.
Trump, though, says that his attitude is always the same, ahead of the quarter-final meeting between the pair at the World Championships.
"Shaun doesn't know me," said Trump. "So he wouldn't know what I do.
"I just go in with the same attitude every tournament and at every one I'm fully prepared to win.
"A couple of times this season it's been a struggle really to get up for it, but at this World Championships I'm fully prepared, and coming in as well as anyone."
In their only previous meeting, Murphy came out on top in the first round of the 2007 World Championships against a 17-year-old Trump.