Novak Djokovic has split with coaches Radek Stepanek and Andre Agassi.
The former world number one, a 12-time Grand Slam winner, is battling back from a long injury lay-off and lost his opening match at the Miami Masters two weeks ago.
"After Miami, Novak Djokovic and his tennis coach Radek Stepanek decided to end their cooperation," read a statement on the Serbian's website.
"The co-operation between Novak and Andre Agassi has also ended."
Djokovic, who has dropped to 13th in the world rankings, missed the final six months of 2017 due to an elbow injury.
The 30-year-old eventually underwent surgery after a disappointing fourth-round exit at the Australian Open in Melbourne.
He had been working with former world number one Agassi since May 2017, while Czech Stepanek joined the team in December.
"The private relationship with Stepanek was and will remain great, and Novak has enjoyed working with him and learning from him," the statement continued.
"Novak remains focused and eager to come back stronger and more resilient from the long injury break that has affected his confidence and game.
"He is continuously and passionately looking for new and different ways to regain winning form."