Football Federation Australia has confirmed Matildas forward Kyah Simon has suffered a torn Anterior Cruciate Ligament (ACL) in her right knee and is set to be out of the game for 12 months.

Simon suffered the injury just seconds after entering Sunday’s (Monday AEDT) international against USA in San Antonio as a second-half substitute.

“It’s obviously a disappointing setback,” Simon said from the USA. “I’m grateful to have such an experienced support staff around me to already have my rehab and recovery process under way and I look forward to coming back stronger than before.

“Every athlete has their setbacks, this one has been an unlucky one for me. My main focus for the next 12 months is my rehab, doing as much as I can within the restraints and returning for the W-League in 2014 and the World Cup in the 2015.

The 22-year-old has enjoyed a stellar year at club level, scoring and being named player of the match in last year’s Westfield W-League Grand Final win for Sydney FC. More recently Simon was one of just four Aussies featuring in this year’s inaugural season of the fully-professional National Women’s Soccer League in the US, where she played for Boston Breakers.

Simon was also one of several major signings by Western Sydney Wanderers for the Westfield W-League which commences next month.

“I was looking forward to the season ahead in the W-League with a good group of players at Western Sydney Wanderers,” Simon said. “Although I won’t be on the park I will still be involved off-field and will be sure to share my support and knowledge throughout the season.

“As hard as it is to sit on the sideline, I know the squads I represent have depth and quality and I wish the Matildas, Wanderers and Boston Breakers all the best in their upcoming campaigns. I’ll be keeping a close eye on all their upcoming games.”

Simon's injury has also big implications for Matildas with the striker now set to miss Australia's 2014 Asian Cup defence.

Kyah Simon will undergo surgery in the coming days upon the Matildas return to Australia.