The governing body of men's tennis has been criticised for not joining the Women's Tennis Association in suspending tournaments in China over the treatment of former doubles world No. 1 Peng Shuai.
The Association of Tennis Professionals, in a statement released a day after the WTA opted to take decisive action given concerns surrounding Peng and the safety of other players, said it will continue to monitor the situation.
"The situation involving Peng Shuai continues to raise serious concerns within and beyond our sport," ATP chairman Andrea Gaudenzi said.
"The response to those concerns has so far fallen short. We again urge for a line of open direct communication between the player and the WTA in order to establish a clearer picture of her situation.
"We know that sport can have a positive influence on society and generally believe that having a global presence gives us the best chance of creating opportunity and making an impact."
When asked by Reuters whether the ATP had any plans or was considering whether to suspend Chinese operation, the governing body said it had no comment beyond Gaudenzi's statement.
In a post on Twitter, 18-time Grand Slam champion Navratilova called the ATP's response "embarrassing", adding: "Are we to understand that the @ATP would have made the same statement had the player been a male? Somehow I think not."
Replying to an image of the ATP's statement, former world No. 1 Roddick said: "How to say a lot of words and say nothing."
Peng's whereabouts became a matter of international concern after a nearly three-week public absence after she posted a message on social media in early November alleging that Zhang Gaoli, a former vice-premier of China, had sexually assaulted her.
Peng, a three-times Olympian, appeared in mid-November at a dinner with friends and at a children's tennis tournament in Beijing, photographs and videos published by Chinese state media and by the tournament's organisers showed.
The International Olympic Committee said it had held a second video call with Peng this Wednesday after one late last month.
The WTA, whose decision could cost it hundreds of millions of dollars in broadcasting and sponsorship, was applauded by many in the tennis community for taking the stand it did, but the ATP is not ready to follow suit.
The International Tennis Federation, which is the governing body of tennis, said in a statement sent to Reuters after its board meeting on Thursday that it stands in support of all women's rights.
"Our primary concern remains Peng Shuai's wellbeing. The allegations Peng made must be addressed," the ITF said. "We will continue to support all efforts being made to that end, both publicly and behind the scenes."
Information from Reuters contributed to this report