A crestfallen Ana Ivanovic ruled out retiring after the out-of-sorts former world number one was dumped from the US Open first round for the second successive year on Tuesday.

The 28-year-old Serb bowed out on day two at Flushing Meadows after she was beaten 7-6 (7-4) 6-1 by the unseeded Denisa Allertova.

Ivanovic also fell at the first hurdle at Wimbledon last month, putting her loss to Ekaterina Alexandrova down to a wrist injury, before suffering defeats in the first round of the Olympics and the Western & Southern Open.

The 2008 French Open champion, now ranked 31st in the world, has no plans to quit, but knows she must go back to the drawing board after her latest setback.

Asked if she could retire, Ivanovic said: "No, not at all. I just need to really see why this is happening,

"I mean I had struggles throughout my career; I had some tough times. This is not the first time I'm going through this. It just hurts because I know what I invested.

"I feel like I have the potential and game, but it hasn't really been coming together. I had four people travelling with me trying to make sure I'm on the right path and doing the right things.

"Before when I travelled with one or two people I was doing much better. These are the things I have to think about."

Ivanovic made 41 unforced errors and coughed up seven double faults, but said her loss of form has not been down to a lack of commitment.

"I really feel like I have to reassess because I have been putting so many hours on court and in the gym in particular trying to get my body healthy," she added.

"It's been very frustrating not getting anything in return, because I really feel like I invested my heart."