Rovers are favourites to win the Carling Cup tie against league one’s bottom club who were beaten at home by Preston at the weekend.
Rovers on the other hand beat Arsenal 4-3 albeit with two own goals from the visitors, but the win has lifted spirits around the club.
But Kean says that the London outfit are not to be taken lightly and he will be doing all he can to make sure his side do not slip up.
Kean told Sky Sports: "It can be a banana skin if you approach it in the wrong way. We will give it the same detail of preparation as we did before Arsenal.
"We are not approaching it thinking we are going to take our foot off the gas. It is the opposite because we want to start with a good tempo, try to get as many goals as we can and keep a clean sheet.
"We have to keep the momentum going so let's use the competition to go as far as we can, all the way if possible.
"They (Orient) have nothing to lose in one respect but I wouldn't imagine they would want to come to Ewood and get hammered.
"I wouldn't imagine, if they have done their reports from the Arsenal game, they will be looking forward to coming to our place.
"If we can score that number of goals against Arsenal I am sure there will be a little bit of fear. If they want to come and be open and have a go and play as if they have nothing to lose then there is a danger in that as well."