British number one Kyle Edmund is looking for another coach after parting company with Mark Hilton.
Edmund lost to Chilean Cristian Garin in the Chengdu Open first round on Monday, his fourth straight defeat.
However, Hilton was not in China for the match as the partnership came to an end last week.
BBC Sport understands it was the coach, rather than the player, who suggested it was time for a change.
Edmund is ranked 32 in the world but, hindered by knee problems, has only managed to win 12 matches on the ATP Tour this year.