While the midfielder did not do any contact work, he is confident of proving his fitness for the sudden-death final at the MCG.
Petracca suffered a hairline fracture of his fibula as well as a corked calf in a collision with Lance Franklin during last week's qualifying final loss to Sydney.
The 26-year-old trained with Melbourne's main player group on Tuesday and while he said the leg is "pretty sore", the club released a statement saying Petracca had proven his fitness.
"I had a pretty good session today ... it's not actually the hairline fracture or the chip, it's the actual 'corky'," he told AFL360.
"It's restricting underneath the knee.
"I trained fully today, I was out of the contact stuff - I could have done it, but didn't need to.
"I have to tick off a few more targets on Thursday at our captain's run, but it's all going well."
Petracca said he went to hospital early last Saturday morning for scans after feeling pins and needles in the injured leg.
He has since been through intensive recovery, including time in a cryotherapy machine at extremely cold temperatures to help the calf heal.
"I knew I did something straight away ... I thought it was something more significant, in terms of an actual knee injury. It was quite tough," he said.
"I want to be out there on Friday night, 100 per cent.
"I don't want to miss it for anything.
"I ticked off a really good box today in main training."
Petracca noted he was also able to play out Friday night's game despite the injury and felt he improved in the second half.
"It's not broken - that's probably the one thing that has frustrated me, your mindset around it," he added.
"It's not a broken leg, it's stable, the doctors have fully cleared me of that and told me it's not going to cause any further injury.
"That's put my mind at ease a lot ... it is just a corky and I can go out there and play."
Melbourne club doctor Laura Lallenec also said the cork to his calf was the harder part of the injury.
"Thankfully, it's really settled down and he's done everything right. We've discussed his injury with a specialist and they're really happy that this injury is stable and that he's safe to get out there and play," she added in a club statement.
The Demons also received good news on two other injuries.
Forward Bayley Fritsch, who experienced knee soreness during the warm-up of the qualifying final, has returned to full training after scans cleared him of any damage.
Fellow forward Charlie Spargo is also set to face the Lions after being cleared of any fractures to his airway following a knock to his throat.
Brisbane midfielder Hugh McCluggage dismissed suggestions the Lions would target Petracca's injury if he took the field.
"It is pretty hard to target someone's legs," he said.
"We learnt last time we played them that if your thoughts are elsewhere and you are not attacking the ball and worrying about the things you do, then things go downhill pretty quickly."
33°C