Maria Sharapova has announced that she has parted ways with coach Sven Groeneveld 'by mutual agreement' after four years.
The 30-year-old won the French Open in 2014 in her first year working with Groeneveld and remained under the stewardship of the Dutch coach during her 15-month doping ban.
The former world number one has endured a tough start to 2018, however, winning just five competitive matches all year.
"After four successful and challenging years of collaboration together, I would like to thank Sven for his incredible loyalty, work ethic and most importantly the friendship that we have formed that will go beyond this working partnership," Sharapova said in a statement.
"Although we have mutually agreed to part ways during this time, I have been incredibly fortunate to have a team leader like him in my corner."
Groeneveld added: "Maria has been one of the most hardworking and professional players I have ever worked with. Her strength and fighting spirit will continue to be a force to reckon with and I have the deepest respect for her as a player and person."
Earlier this week Sharapova suffered a shock first-round exit from Indian Wells at the hands of Japanese number one Naomi Osaka.