"I am no longer working with Johanna but I want to give Johanna the opportunity to speak about it rather than me," coach Esteban Carril told the Daily Mail.
There was no immediate comment from the 25-year-old Australian-born player.
The BBC said the British number one, who was ranked 147 in June last year but reached the semi-finals of the Australian Open in January and won her first WTA Tour title at Stanford in July, was now training at the National Tennis Centre in Roehampton.
She secured a place in the top 10 in October -- the first British woman to rise so high in the rankings since Jo Durie in 1984 -- when she reached the China Open final and was voted the WTA's most improved player of 2016.
--reuters--