Angelique Kerber revealed it was "the right time for a fresh start" after announcing she has parted ways with coach Rainer Schuttler.
Former Australia Open finalist Schuttler only started working with the three-time grand slam champion last November, taking over in the role from Wim Fissette.
However, world number 13 Kerber – who made it through to the final at both Indian Wells and Eastbourne but is yet to win a title in 2019 - posted a message on Twitter to confirm the split from her fellow German.
"Moving forward, it's never easy to change – especially when you work with great people like Rainer," Kerber said.
"But for now, we’ve decided that it's the right time for a fresh start. He has become a friend and I'm thankful for his hard work and dedication in the last months."