Polish star Iga Swiatek has split with her coach Piotr Sierzputowski after nearly six years working together.

“This change is really challenging for me and this decision wasn’t easy, either,” Swiatek wrote in a post on Instagram.

Swiatek, 20, hired Sierzputowski in January 2016, when she was 15 and still playing in junior tournaments.

“I would like to thank you Coach for everything that you did for me. We gave each other so much and I hope that we’ll continue to grow and develop with this experience we’ve gained together,” Swiatek wrote.

“I owe you a lot and truly appreciate the time we’ve spent together. All those years enabled us to be in the place that we are now.”

Swiatek did not say who her new coach would be.