Former US Open champion Samantha Stosur has insisted that she is capable of winning another Grand Slam title.

The 31-year-old, who won at Flushing Meadows in 2011, has not gone beyond the quarter-finals of a Major in the last two years.

However, the Australian has claimed that she still has what it takes to challenge for the main prizes.

"Look, I don't see why [I cannot win another Grand Slam]. It's obviously very difficult, and you don't know, and you've got to work your butt off and a lot of things have got to go right for that fortnight," she told the Sydney Morning Herald.

"But, I feel like if I'm able to train and do all these things, I still think that when I'm playing my best. My tennis is still good enough to do very well. Whether that's to win a Slam, who knows. But I still feel like I'm capable of having good results."

Stosur, once the world number four, is currently ranked in 27th position.