KEY POINTS:
Casey Williams has done some serious growing up in the past six months.
Physically, the 22-year-old hasn't stopped growing; she's added another 2cm to her lean, agile frame since May. At 1.88m, she's now the tallest of the Silver Ferns defenders and only two notches off standing eye-to-eye with Irene van Dyk.
Mentally, she's grown smarter, she says. With the help of Silver Ferns medical experts and university lecturers, Williams has learned how to take care of those forever lengthening legs - perhaps the most precious pins in New Zealand sport right now.
The daughter of a Waikato cow cockie, Williams has played just 18 tests for New Zealand but is already seen as the first-choice goal keep going into next week's world championships.
Predictions are she will be one of the great Silver Ferns defenders.
"Casey continues to amaze all of us. When you see her in flight after hunting down an intercept she's the most spectacular player," says former Fern goal keep Tracey Fear. "For a young player to be able to play as she does is so exciting for the Silver Ferns now and for the future."
Williams' joints haven't been the most reliable in her short but explosive career. An exceptional defender with a stunning leap and an eye for an intercept, she first met the Australians in the final of last year's Commonwealth Games playing with a fractured ankle, and missed the end of season series against Australia with a knee injury.
A heavy fall in the National Bank Cup in April aggravated the knee again on the eve of touring the UK.
Her injury problems were exacerbated by not understanding how to manage them, how to rehabilitate and strengthen, and to know when to rest. But Williams has been learning how to take care, even studying physiology at university.
Her new-found understanding of her battled-scarred knees will come under the first practical test next weekend in the opening game of the world champs, which pits the Ferns against the unpredictable Malawi Queens.
At the end of the month, she will be tested on the theory side of her knowledge, a university exam on "human biology and chemistry concepts" towards her bachelor of sports science degree.
Her goal in the build-up to these world champs was to work on her strength and conditioning: "So I knew if I got knocked over, I could bounce back. Personally I think I've done everything I can to be ready. I know I've done the rehab and the strength training to bring my knee back to 100 per cent," she says.
"I know more about my body now. I would usually keep going and going until something else happens. But now I understand if you don't rest it can set you back further. It's about being smart."
She's backed it up with her studies in the last few months, doing one paper this semester at Wintec in Hamilton towards her sports science degree (her aim is to become a PE teacher).
"It's good knowing what's going on with your body, so when I go for a run, I know which muscle is doing what, and why something hurts," she says.
Her human biology exam was to be on November 12, the day the Ferns play their second pool match against Wales, but she's been allowed to postpone it for a fortnight. After all, the nation has its hopes pinned on her to succeed on court.
"A lot of people are saying 'it's up to you now', but we don't think like that. We've already put the pressure on ourselves," she says. "Sure, we want to win it for New Zealand, but first and foremost we want to win it for ourselves, because we know how hard we've worked for it."
Although this will be Williams' first world championship, it's not long ago she won a world title with the New Zealand under-21s - the 2005 World Youth Cup. Alongside her were fellow Silver Ferns Maria Tutaia and Laura Langman.
"It's really cool, really exciting, to share this experience with Maria and Laura," she says. "We know about pressure, but the expectations are so much higher this time. It's good to have them next to me."
Not that Williams needs hand-holding. She's grabbed with two hands the opportunity to be the number one goal keep in the wake of Vili Davu's retirement last year.
She was never afraid of the expectations, "It's been good to be put out there. They place responsibility on you, so you need to stand up and take it," she says.
An adept reader of the game, Williams revels in the gritty competitiveness of Australia's shooters, and snatching the high lobs of the Jamaicans' aerial game.
"I'm competitive and aggressive when I'm out there - if I want to get the ball I will do my best to get it. I still play for fun, but I don't think I could turn off the competitiveness in me," she laughs.
She's also looking forward to a re-match with Malawi, who had her on the run in the opening stages of last year's Commonwealth Games encounter.
"At first it was a bit of a shock to me - I didn't count on a team making 64 passes between each other before scoring their first goal. We're better prepared for them this time though."