Johanna Konta is looking for a new coach after parting company with Esteban Carril.
The British number one, who reached the top ten for the first time this year and was voted the WTA most improved player of the year, revealed the decision was agreed jointly between them.
She said: "After two and a half successful years working together we have mutually agreed to explore new options," adding: "Once things are confirmed we will share the new set-up."
With Konta having lost the services of her 'mind coach' Juan Coto, who died last month, she will now need to choose well if she is to continue her dramatic progress of the last two seasons.
The 25-year-old has credited Coto with helping her develop the mental side of her game, but the work done with Carril and fellow coach Jose-Manuel Garcia has also had a huge positive impact on her technical skills.
Having reached her first Grand Slam semi-final in this year's Australian Open, Konta is now a genuine contender for the big prizes and it could be that the right coach in 2017 could take her to the next level and give Britain another tennis champion.
Fans booking corporate hospitality for the Championships, Wimbledon can already revel in Andy Murray's two men's singles titles at the All England Club, as well as his new status as world number one. Add to that Jamie Murray's position in the world's leading men's doubles partnership alongside Bruno Soares, and Britain's tennis cup will be running over if Konta can give the women's game the same superstar profile.
Konta's run to the semi-finals in Melbourne made her the first British woman to reach the semi-finals of a Grand Slam since Jo Durie in 1983, but it was not just in the biggest events that she thrived. She took her first WTA tour title at Stanford in the summer and was a finalist at the China Open. She was also very close to reaching the WTA World Tour Finals in Singapore.
Currently training in Roehampton ahead of the start of the new season, Konta will be sizing up her options carefully as she considers who could take her a step further. With Serena Williams now aged 35 and no longer world number one, there may be a golden opportunity in the next couple of years for a new dominant player to emerge. Konta will hope to be that player.
Alternatively, it could be that no one player comes to dominate the way Serena Williams has, which would make the field very open at every big tournament. Either way, big opportunities await.
Johanna Konta is not the only player to announce a change of coach. This year's men's runner-up at Wimbledon Milos Raonic has announced he is parting company with Carlos Moya.
The Canadian, who has also worked with John McEnroe this year and has Riccardo Piatti as his full-time coach, said he and Moya will remain "close friends" despite the split.
As well as reaching his first Grand Slam final, the 25-year-old recently played in the ATP World Tour finals for the first time and has ended the year with a career-high ranking of third.