Halifax are currently third in the Kingstone Press Championship table, four points adrift of Sunday’s visitors to The Shay.
Harrison said: “We played well and, while I was disappointed with the final scoreline, it was a tough encounter.
“We’ve got a good bunch and a good team. We need to finish up there in first or second, and that (against Widnes) will set us in good stead.”
Leigh coach Paul Rowley insists Halifax are the division’s standard bearers.
Rowley said: “I’ve said from day one that Halifax have got the best squad in the competition this year.
“We came up with a few basic errors against Rochdale last week, and Halifax would thrive on that if we do it again. If you give them enough possession, they’ll punish you. They like playing good rugby and they’ve got some very dangerous players.”