Two-time Wimbledon champion Petra Kvitova is without a coach for the second time this year after firing former doubles specialist Frantisek Cermak to end a partnership that began in April.
Kvitova announced her decision in a statement to local media after she returned from the US Open, where she was eliminated by second-seeded Angelique Kerber 6-3 7-5 in the fourth round.
In January, Kvitova terminated her seven-year partnership with coach David Kotyza. That came after she was eliminated from the second round of the Australian Open.
Kvitova has been struggling since, and is ranked 16th. Her major success this year was the bronze from the Rio de Janeiro Olympics.
She says she has nobody to replace Cermak immediately.