Nick Kyrgios has withdrawn from the Atlanta Open with an ongoing hip injury but hopes to be back for next week's event in Washington.

The 22-year-old Australian issued a statement via the tournament organisers to express his dismay at not being able to defend the title he won on the hard courts of Atlantic Station.

"Having to make the decision not to defend my title at the BB&T Atlanta Open was really tough and disappointing," said Kyrgios, adding that his hip was "just not ready".

The world number 20 has not played since retiring from the first round at Wimbledon when two sets down to Pierre-Hugues Hebert.

Kyrgios hurt his hip when he fell on the slippery grass courts at Queens in June.

He said that he still plans a return in a week at Washington, adding that he will be ready to play the US Open starting August 28.