Despite enjoying periods of clear dominance against the Cats, Fremantle kicked its way to defeat, with Chris Mayne, Adam McPhee and captain Matthew Pavlich all missing chances in the final term.
Harvey's side won the clearance battle 39-29, and it had eight more inside 50s than the visitors, but the Cats kicked straighter and left Fremantle to contemplate a crushing home loss.
"The supply was there, it's just the ability to be able to finish," Harvey said after the match. "We owned a lot of the play but couldn't convert.
"We've learnt a harsh lesson here at home, and it's not something that sits well with us.
"When you play at home you need to put some self doubt into the [opposition] team and get in front and make sure there's an intimidation factor about playing here.
"But if you're consistently not kicking straight then they're feeling like they're on top of you and that they're a genuine chance. That's a problem."
Fremantle midfielder David Mundy (29 possessions and a goal) and Pavlich (28 possessions, seven clearances and a goal) led the way for Fremantle, but the side couldn't edge in front after the nine-minute mark of the first quarter.
"We were just always fighting," Harvey said. "We never got ourselves into a position where we could control the game.
"That can put some tension into the state of the game and sometimes players can feel that. But they shouldn't.
"There are other issues in our game at the moment that we need to tidy up, [like] just not being clean at the right time.
"Particularly if you can catch the opposition on a fast break and you're not necessarily clean when you need to be."
Geelong made three changes to the side it selected on Thursday afternoon, with Daniel Menzel, Cameron Guthrie and debutant Allen Christensen all included on Friday.
Harvey said it was strange that the visitors were forced to make three changes to their selected side, with Joel Selwood withdrawn with concussion and Cameron Mooney (soreness) and Tom Lonergan (calf) not deemed fit.
"It didn't throw us out, because once you know you know," Harvey said.
"(But) the fact that there was three late changes made is an issue I think. To make three changes from a Thursday to a Friday is strange."
Harvey said utility Garrick Ibbotson and key defender Alex Silvagni were likely to play next week, either in the WAFL or at senior level, with Fremantle travelling to AAMI Stadium to take on Adelaide.
"We've got a couple of players hopefully coming back in coming weeks, but you've just got to make sure that they're fit enough to be able to cope with these new rotations," the coach said.
