Sandilands took a knock to the knee in a ruck duel with Hawk Wayde Skipper late in the first quarter, and he was forced to play out the match as a deep forward.
Harvey said the crucial big man would have scans on the injured knee but initial signs were positive.
“We’re sort of optimistic about him; we tend to think he’ll be okay,” Harvey said after the 30-point win at Subiaco Oval.
“It’s sort of a direct knock to his knee cap at this stage. If there’s any other damage we have to wait, but it was a direct blow to his knee.
“They (the medical staff) are reasonably confident they can get him up for next week.”
After winning nine hit-outs in the opening term, Sandilands finished with 18 ruck taps and a goal, and Harvey said he was a viable option as a permanent forward on Friday night.
“It just gives you a different dimension down there at times,” he said.
“We had to push him forward [and] I thought he was effective for us.”
Fremantle will travel to the MCG for the first time this season, with its last fixture at the ground back in round 20, 2009. It hasn’t won there since early 2007.
However, Harvey said his young players, who stood up in their first final on Saturday, would feel no fear against the reigning premiers.
“Playing at the MCG on Friday night [is] a big occasion for our guys, [but] as you saw today, they’re not daunted by the finals,” he said.
“I think that if you’ve got five- or six-gamers playing in a final and they acquit themselves pretty well … it should hold you in good stead.
“They’re a great, elite midfield and we know what we’re up against.”
Harvey praised defenders Luke McPharlin and Antoni Grover, who contained Hawthorn spearheads Lance Franklin and Jarryd Roughead for most of the match.
Adam McPhee was influential in a tagging role on Luke Hodge, while Ryan Crowley was also singled out by the coach for his job on Clinton Young.
“There was a number of match-ups that we had going into the game [and] they all tended to work for us,” Harvey said. “That’s not always the case.
“I thought three or four of our match-ups [worked] and the way we planned for Hawthorn gave us an advantage.”
“We were playing a side that was moving into this finals series as probably a major threat as to what was going to happen.
“We managed to defuse a lot of the things they’ve been good at.”
