Caroline Wozniacki has decided to remove her father Piotr as her coach.
The world number one has endured a tough run of form, losing in the opening rounds in both Toronto and Cincinnati in recent weeks.
The 21-year-old has decided to make a change of coach as she bids to rediscover form ahead of the US Open later this month.
"I am no longer her coach. Who will be the new one? I promised I wouldn't say," Piotr Wozniacki told the Ekstra Bladet newspaper.
"From morning to night, we have heard how Caroline should play. Now we are trying something else. I am Caroline's father and I will always support her."
Wozniacki lost in the fourth round of Wimbledon for a third successive year in June and has yet to win a Grand Slam tournament.