Many consider the Mystics' chances in Melbourne this weekend to hinge on the fitness of the Silver Ferns defender.
Harrison was the star in what was a strong all-round performance from the Mystics in their shock win over the Vixens in their round eight meeting earlier this year.
In that match, the Mystics debuted their controversial defensive lifting tactic, with the Vixens shooters left dumbfounded when Harrison was hoisted into the air to block theirshots.
The assisted goal-tends drew booing from the home crowd, and with upwards of 10,000 fans expected to turn out for this weekend's playoff match, the Mystics can expect an even more vociferous reception on Sunday.
With the Vixens' regular venue booked out, the fixture will be held at Rod Laver Arena - a first for netball. The franchise has released 10,000 tickets for the match, but has the option of releasing a further 4000 seats should the demand warrant it.
Mystics shooter Cathrine Latu said she was not intimidated by the prospect of playing in front of what could be a record crowd for the transtasman league.
"It could get very loud in there, but I have selective hearing anyway," said Latu. "It is going to be a very different atmosphere, but they're still the same players with the same strengths and weaknesses."
The winner of this weekend's match in Melbourne will advance straight through to the ANZ Championship grand final and earn a week off, while the loser will battle it out with the winner of Monday night's minor semifinal between the Magic and Thunderbirds.