Former Aston Villa defender Ron Vlaar is in limbo after suffering a serious knee injury.

The Sunday Mirror says Vlaar's hopes of finding a new club have taken a blow, after the Dutch international was ruled out of action for up to six months with a knee injury.

The 30-year-old defender left Aston Villa last month following the expiration of his contract, following three years at Villa Park.

The Dutchman is now highly unlikely to play again in 2015, after undergoing a second surgery in six months.

Southampton and Lazio has been keen on signing Vlaar this week.

"Part of being a professional athlete is learning how to deal with setbacks in your career, and having the mentality to come back stronger," declared Vlaar in an open letter.

"I have faced tougher situations in my life and always managed to overcome them. I am proud of what I have achieved in my career and I am positive that with the support of the people close to me I will come back stronger again.

"I am already starting to feel the energy flowing through me, the button has been pushed and my mind is completely focused. There is only one thing in my mind and that is to be completely fit again!"