Claudio Ranieri's reigning Premier League champions, who find themselves in 17th spot in the league, will travel to the League One club for the fifth-round tie at The Den on Saturday.
"We need to get on the front foot in terms of intensity, and if we do that, I think we can hurt them with our creative attacking play," said veteran striker Morison.
"Right now they're having a bad patch of form and I think we can prey on that fragility when they come to The Den.
"I've been enjoying playing Prem teams, and I've actually found the games quite comfortable. They're not as physical as the games we have in the league, so it's more about bringing your quality to the fore."