Paris - Tennis legend Martina Navratilova ended her four-month coaching link-up with Poland's Agnieszka Radwanska on Friday, claiming she was unable to dedicate enough time to the job.
Navratilova, an 18-time Grand Slam singles champion, joined the 26-year-old's coaching team in December with the task of helping the world No 9 win a first major.
"I am stepping down as Agnieszka's part-time coach. I think I under-estimated the time it would take to make this a proper and good situation for both Agnieszka and me," 58-year-old Navratilova said in a statement.
"I really enjoyed working with Aga and her whole team and I wish her all the best for the rest of the season."
Radwanska, a Wimbledon finalist in 2012, ended last year at six in the world but has struggled in 2015 with a single semi-final place in Katowice her best effort so far.
She was beaten in the first round in Stuttgart by Italy's Sara Errani this week.
"I just wanted to thank Martina for her time and efforts over these last few months," wrote Radwanska in a statement on her Twitter account.
"It was a great experience but we both agreed that as Martina could not commit 100 percent to the project then it was not going to work as a long-term partnership."