Petracca was proppy throughout Friday night's 14.7 (91) to 10.9 (69) qualifying-final loss to Sydney at the MCG after copping a stray boot to his upper right calf in an awkward first-quarter collision with Lance Franklin.
The Norm Smith Medallist had scans on Saturday which confirmed a "minor" fracture but the Demons were more concerned about the corked calf that limited him against the Swans.
"The advice from our medical team is that a fracture of this nature will not rule Christian out of selection for our semi-final," Melbourne football boss Alan Richardson said in a statement.
"The fracture poses no further risk to Christian and will not impact his ability to play.
"What will pose more of a challenge for Christian is the corky he sustained to his calf in a collision that occurred in the first quarter and hampered his movement for the majority of the match against Sydney.
"Obviously Christian will need to tick some boxes throughout training this week but we are confident that he will be ready to go come Friday."
Petracca lacked his usual explosiveness due to the contusion in his calf, but played out the game and battled his way to 24 disposals and four clearances.
"He was pretty sore," coach Simon Goodwin said.
"Clearly, it limited his movement for the majority of the night and had a bit of an impact on his game."
Forward Charlie Spargo went to hospital post-match as a precaution after a blow to the throat left him unable to speak and he will be assessed, as will Bayley Fritsch.
Fritsch pulled up sore after he pushed through pre-game concerns over his knee to kick three goals.
Clayton Oliver had stitches on his eyebrow and cheekbone but Goodwin said there were no concerns over a potential fracture.
Tom McDonald, who recently returned from a foot injury via the VFL, was due to complete a big training session on Saturday but Goodwin wouldn't be drawn on whether he'd call upon the athletic tall.
The Demons will want to toe the line more against Brisbane after Goodwin was frustrated with multiple lapses in discipline against Sydney.
That included three 50-metre penalties that cost goals and utility James Harmes being reported for a high, late hit on Swans defender Jake Lloyd.
"Finals footy's about getting the basics right for a long period of time and you need to be a disciplined footy team all the time," Goodwin said.
"So if you give away 50-metre (penalty) goals or downfield free kicks or give up territory through downfield reversals that cost you goals, that hurts.
"In tight games, where the stakes are high, that hurts."
