Sam Kerr opens up on why she kept her gender a secret as a junior footballer

Matildas striker Sam Kerr has revealed she had to masquerade as a boy just to get a game as a junior footballer before being forced to quit playing for her team because she was being left with black eyes due to rough play.

The Matildas dream run through the FIFA World Cup is shattering both the perception of women's sport and TV viewing records in the process - but Kerr's memories are a reminder that Australian soccer still has a lot of work do.

Writing in her new book My Journey to the World Cup, the Chelsea striker recalls cropping her hair short and pretending she was a boy for five to six years as a junior so she could get on the pitch in East Fremantle, just south of Perth.

'I knew I'd be the only girl on the team but that didn't worry me at all,' Kerr wrote.

'I didn't want them to treat me any differently just because I was a girl.

'I remember one of the boys crying when he found out.'

Kerr gave as good as she got early on, but eventually the physicality became too much and her family had to intervene when she came home with shocking injuries.

'As good as I was out on the field, and as much as I loved playing the game, the physical differences between the guys and me eventually became too pronounced and the play was too rough,' she wrote.

'One day, I came home from a game with yet another black eye and bloody lip, and that's when my dad and brother both said, 'Nup, this isn't happening anymore'.

'I was getting battered around so much out on the field that it was getting to be a big problem. Dad and my coach both sat me down then and said it was getting far too dangerous for me to continue to play.

'They said they were sorry, but that I wasn't allowed to play football any more. I understood the reasons why, but I was