Proceeds from Rally for Bally will be split between the Royal Marsden Cancer Charity, a world famous London hospital in the fight against cancer, and the Elena Baltacha Academy of Tennis (EBAT), which the Scot founded and runs for disadvantaged children in the Ipswich area.
Murray and Navratilova will join the likes of Tim Henman, Greg Rusedski, Jamie Murray, Heather Watson and Laura Robson for one of three events, played simultaneously on June 15.
You would be hard pushed to find anyone who has met Baltacha to offer a bad word about the 30-year-old, who reached a career-high ranking of No. 49 in 2010.
Perhaps only the endearingly modest Baltacha herself would have been surprised at the outpouring of support and Judy Murray, the Britain Fed Cup captain and a long-time friend, said Baltacha would be hugely touched.
"I think she'll be blown over by it," Murray told Herald Sport. "I know she's been looking at some of the messages on Twitter and Facebook and has been quite bowled over by the volume of messages that have come through and she will use that support to keep her strong and help her to fight this.
"I've known Bal since she was nine," she continued. "Obviously, in the last few years, I have become very close to her again through the Fed Cup and [through] trying to help her with her own tennis..
"In all the years that I've known her, I don't think I've known a better competitor or a better fighter. I have seen her battle through a number of pretty serious injuries and illness and knowing how tough she is mentally that is going to stand her in very good stead for this latest battle."
Navratilova will join Anne Keothavong, Henman and Jamie Murray in Birmingham at the Aegon Classic, while former Wimbledon doubles champion Jonny Marray and Rusedski will play at the Aegon International.
Navratilova, who overcame breast cancer in 2010, said yesterday: "My thoughts are with Elena and what she must be going through at this time. It is great that the tennis world is coming together to support her and to rally against cancer."
What might touch Baltacha even more than the support of the stars - and the Lawn Tennis Association - is that from some of her own academy. She has put heart and soul, as well as some considerable money, into trying to give disadvantaged young children the chance to get involved in tennis.
One of the donations on her Just Giving page yesterday, which had received dozens of donations within hours of opening, came on behalf of a girl at EBAT called Elle.
"That's fantastic," Murray said. "That just went up this morning. I think there will be a lot of support. It's very rare you meet anybody who hasn't been touched by cancer, whether through a friend or a family member and the fact that Bally is so young, was still active and so fit, just shows you that it can hit anybody at any time. I think that will strike a chord with a lot of people."
The events follow last year's Rally Against Cancer, held at Queen's Club and set up by the British doubles player Ross Hutchins, who was given the all-clear last summer after battling Hodgkin's Lymphoma. Hutchins, who is now also the tournament director of the Aegon Championships at Queen's, will take part in a mixed doubles along with Andy Murray.
Judy Murray said the money raised for EBAT would help to continue Baltacha's good work. "When they set it up it was aimed at going into schools in disadvantaged areas in the Ipswich area, where she lived, and creating opportunities for little girls, in particular, to try tennis," she said.
"It was then about selecting a number of them who were keen and maybe had some reasonable coordination skills, to give them a tennis programme and fairly well subsidise that in order to give them a chance to progress.
"So there is a dual focus: the fight against cancer and the opportunity to create some sustainability for the academy, while she and her husband Nino [Severino] are unable to work, and to make sure that can carry on into the future."