Shipard announced her decision on Tuesday after more than a decade at the top.

The Canberra United and Australian Matildas midfielder has been battling to overcome constant knee problems for two years and finally decided the pain wasn't worth it.

Shipard rocketed on to the Australian soccer circuit as a teenager and played at the Athens Olympic Games in 2004.

"The passion I developed chasing leather took flight long ago, and imagining my life without football is difficult to fathom," Shipard wrote in her FFA blog.

"Deep down I recognised this quest would eventually come to a halt, but perhaps not at 26 years of age. [But] following deep contemplation, I'm retiring."

Shipard, currently in the US, will miss the chance to play for the Matildas at the World Cup next year.

Shipard bravely opened up in 2011 about her battle with bulemia in the hope her story would inspire others to get help after fighting her inner demons during her career.

She played 62 games for the Matildas and won a W-League championship with Canberra United in the 2011-12 season.

But a playing stint with German giants Bayer Leverkusen was the start of a nightmare injury run which led to Shipard's decision to quit.

She had a bilateral arthroscope to clean up and repair meniscus damage in 2012 and had another arthroscope three months later.

The supremely talented playmaker played just two games in the 2012-13 season for Canberra and just 65 minutes last season.

"A gigantic part of me wants to continue playing. Primarily [my decision to retire] is for physical reasons - my knees continue to swell following running.

"Though it was challenging, I was eternally grateful for the support of my teammates and staff of Canberra United.

"There exists a world away from the round ball, I know that."

Shipard quit soccer in 2008 to get away from the sport in the hope of rediscovering her love of soccer.

She played at the 2007 and 2011 women's World Cups and was part of the Matildas' 2010 Asian Cup triumph.

A Barcelona futsal transfer and contract bungle forced her to sit out of the 2009 W-League season before making her comeback to Australian soccer in 2010.