Martina Navratilova has agreed to take on her first major coaching role working with Agnieszka Radwanska.
The 18-time Grand Slam singles-winner will link up with the world number six at the end of the year.
Navratilova, 58, said: "I can't wait to get started on this new phase of my career and I am really excited."
Navratilova will work with Radwanska's full-time coach Tomasz Wiktorowski, and will train with the 25-year-old for the first time in Miami after Christmas.
The nine-times Wimbledon champion added: "I was delighted when Agnieszka asked me if I would collaborate with Tomasz.
"I did not sleep very well last night, thinking about getting back into match mode and the competitions."
Radwanska, an Australian and US Open semi-finalist, is confident Navratilova's presence will help her earn a first Grand Slam success.
The Pole, added: "Her achievements speak for themselves and I hope that I can learn from all her experience. She is my tennis idol.
"We are originally from a similar part of the world so we share an understanding about tennis and life, which I'm sure will translate into a successful relationship."
Andy Murray welcomed the move. The British number one tweeted "Well done to @Martina and @ARadwanska wish them all the best for next year! Hope it goes well for you both."