Two-time Australian Open champion Victoria Azarenka says her participation in the U.S. Open is in doubt because she might not be able to bring her baby with her to New York as a result of her separation from his father.

Azarenka says via a posting on Twitter on Thursday that she is "faced with a difficult situation which may not allow me to return to work right away."

She says she separated from her son's father shortly after Wimbledon last month. Azarenka says that as they "work to resolve some of the legal processes," she would need to leave her son in California while playing at Flushing Meadows, "which I'm not willing to do."

The U.S. Open starts Aug. 28.

Optimistic differences can be worked out

"I remain optimistic that in the coming days Leo's father and I can put aside any differences and take steps in the right direction to more effectively work as a team and agree on an arrangement for all three of us to travel and for me to compete," Azarenka wrote, "but, more importantly, to ensure that Leo has a consistent presence from both of his parents."

Azarenka was the runner-up in New York in 2012 and 2013, losing in the final each year to Serena Williams.

Those were also the years that Azarenka won her two Grand Slam singles titles in Australia.

Wimbledon was Azarenka's first major tournament in more than a year. She currently is ranked 204th.

"Balancing child care and a career is not easy for any parent, but it is a challenge I am willing to face and embrace. I want to support men and women everywhere who know it is OK to be a working mother — or father. No one should ever have to decide between a child and their career, we are strong enough to do both," Azarenka wrote.

"I am incredibly grateful for all of the support I have received from women and men around the world who recognize the importance of supporting working moms and our right to be with our children," she said. "I look forward to hopefully having positive developments soon so that this difficult situation can be resolved and I can get back to competing."