Federer's official website has released an announcement saying, "After five great years, Stéphane Vivier and I have decided to stop working together. He was a great member of my team and we will always remain close friends. I wish him all the best in the future."
Federer took on former ATP trainer Vivier to travel with him in 2009, looking to stay fit and avoid injuries at tournaments.
For Dimitrov, this appears to be part of a new emphasis on fitness that has seen him climb into the Top 10 this year. The 23-year-old Bulgarian, who has attempted to get away from the nickname of "Baby Federer," is also represented by the agency Team 8, which is co-owned by Federer's agent Tony Godsick and Federer.
Federer has not announced a new physio appointment.