There may not be a lot to Harrison's calves, but they've certainly given her a lot of grief this season.
The Silver Fern missed her side's opening-round win over the Pulse, and has had to manage her delicate pins carefully for much of the season.
Last week's flare-up in Christchurch came after she suffered a minor tweak in the warm-up.
"It's a new problem, but the same area, so it is very frustrating - I'm not the best spectator," said Harrison.
"It's something I'm really going to work on after this and make sure they can handle the endurance stuff."
The delicate timing of her injury means the Mystics have a difficult decision to make over their star defender.
They do not want to risk pushing Harrison too soon and have her do further damage to her calf heading into the transtasman league play-offs.
But there is a small matter of making sure they get to the finals. While the Auckland side are second on the table heading into the final round, a loss tomorrow would make their position in the top four tenuous.
"It'll come down to whether I feel confident enough with it. I don't want to risk getting out there and doing it again and not being 100 per cent for play-offs," said Harrison, a trained physiotherapist.
While the Mystics are confident with their depth in defence, without their chief enforcer they won't strike the same fear in their opposition.
Young gun Kayla Cullen stepped up in the absence of Harrison last week to lead the defensive end, picking up some brilliant ball. But the rookie Silver Fern's preparation still lets her down at times, and she tends to battle in the latter stages of games with cramping.
Fuller believes the Mystics' ability to adjust to the speed and strong ball movement in the Swifts' shooting end, led by Susan Pratley, could be key to her side's success tomorrow.
"We don't want to be reactive in this game, we want to go out there and attack it right from the start. We can't just sit there and think 'oh that ball is going really fast' and then try to think about how we are going to counter it," said Fuller.
All five ANZ Championship matches this weekend will be transtasman affairs, with tomorrow's game in Auckland and the Magic's clash with the Queensland Firebirds on Monday likely to have the biggest impact on the play-offs picture.
Crucial clashes
* ANZ Championship - final round
* Today: 4.20pm Southern Steel v Melbourne Vixens, Invercargill.
* Tomorrow: 2.10pm Adelaide Thunderbirds v Canterbury Tactix, Adelaide; 4.20pm West Coast Fever v Central Pulse, Perth; 7.20pm Northern Mystics v NSW Swifts, Auckland.
* Monday: 7.40pm Waikato/Bay of Plenty Magic v Queensland Firebirds, Hamilton.
