Cassisi suffered a depressed frontal sinus fracture and mild concussion after clashing heads with a Hawthorn player last weekend.
But he has been given the all clear to play this week.
The Western Australian completed half of Thursday’s main training session in the protective helmet before leaving the track with forward Robbie Gray.
Power coach Mark Williams confirmed Cassisi was a certain starter against Fremantle and said he was confident the inspirational onballer would get through the game.
“Under doctor’s orders we looked after Dom at training today because he got a whack in the head on the weekend, but he’ll be no worries,” Williams said on Thursday.
“The safest spot in AFL now is your head. If you’ve played a lot of footy you’ll know that the number of times you get hit in the head, well, it’s very, very rare.
“You back those odds and away you go.”
Veteran Peter Burgoyne, who was dropped from the Power side after round 15, also commanded attention with a strong performance at training.
The Port Adelaide coaches and players challenged Burgoyne to prove he wants to play on next season and Williams said he’d been happy with the premiership star’s response.
“I thought Peter trained well today and I went and watched him on the weekend and he played well too,” Williams said.
“He’s seen the numbers going down in terms of how many games are left in the season and he very much wants to get back in.”
The inconsistent Power will start warm favourites against Fremantle, which has claimed just one win from its past 11 starts.
But Williams denied the game was Port Adelaide’s to lose.
“We have to worry about Fremantle. They matched the Western Bulldogs except for one quarter last week,” he said.
“They have a young, exciting side and they’re building. Every game they play now is money in the bank for next year I’m sure.
“We’re mostly concerned about us and bringing our effort. If we can bring that, we’ll do okay.”
