Despite Hawthorn's crippling injury list and Freo's three-game winning streak, Harvey said he still believed Fremantle was the underdog for the Subiaco Oval clash.
And with the reigning premiers staring at a 3-5 record if they lose, Harvey said he sensed the Hawks were putting a lot of stock in the Friday night fixture.
"The way the inner sanctum is just subtly letting out things or talking about things to the media you can see that they're seeing this game as a big pointer towards what they do throughout the course of the year," Harvey said on Thursday from Fremantle Oval.
"A little bit of momentum that we've got and the fact that they haven't got a lot of momentum at this particular stage – that might be something that we might be able to prey on throughout the course of the game."
Luke Hodge's omission was just another momentum shift away from the visitors, who are also missing first choice defenders Trent Croad, Rick Ladson and Stephen Gilham.
Harvey said both sides would be vulnerable with key players missing but warned Freo would target the Hawks' thin defence.
"He (Hodge) is their director, he's their coordinator, but on top of that he's a great player," Harvey said.
"[His omission] gives us an advantage to look for an opportunity in the position that Luke normally plays – for us to exploit those sorts of things.
"Whether we're good enough or not at this particular stage remains to be seen."
Harvey named Luke McPharlin and Chris Tarrant as likely match-ups for star Hawthorn pair Lance Franklin and Jarryd Roughead, while captain Matthew Pavlich, he said, would continue to plug holes in midfield.
The coach also left the door open for Des Headland to make a return to AFL football this weekend without a preliminary run in the WAFL.
Headland's persistent calf injury has kept him out since the opening round of the season but he was put through his paces during a tough one-on-one session on Tuesday afternoon.
The brilliant but injury-plagued midfielder has been named as an emergency for round eight but Harvey said there might be a late change.
"If it's not this week it'll certainly be next week, " he said, refusing to rule out Headland's chances for Friday night.
Harvey said the prime-time fixture was an opportunity for Fremantle members and supporters to create an intimidating atmosphere at Subiaco Oval.
"If it's a sell out crowd then our players play accordingly," he said.
