The former Morocco international was only a bit-part player under Thomas Tuchel in the 2021-22 season and is expected to head for the exit door in the coming weeks.
Ziyech has been represented by Dutch agency Nakhli Mondial since his days as a youth player at Heerenveen in 2010, but the 29-year-old has announced that he will be representing himself in the years to come.
A statement from the Chelsea man on social media read: "I have reached a point in my life where I feel that the time is right for me to take full control of my professional future.
"I want negotiations and decisions about my career to be made by me. So moving forward, my team and I, together with our legal representatives, will handle the business side of things.
"I am no longer represented by Nakhli Mondial. Thank you for the last 12 years. I am wishing them nothing but the best. I am incredibly grateful for your continued support."
AC Milan are thought to be leading the race to sign Ziyech this summer, with Blues boss Tuchel open to letting the attacker leave should the right offer be made.
The latest update from transfer expert Fabrizio Romano states that Milan and Chelsea are still in talks over a deal for Ziyech, who would welcome the chance to join the Serie A champions.
Milan boss Stefano Pioli is said to be seeking a number of attacking reinforcements for their Scudetto defence and is also working on a deal for Club Brugge's Charles De Ketelaere.
Olivier Giroud remains on the books at San Siro, and a new deal could soon be agreed with Zlatan Ibrahimovic, but the 40-year-old is out until 2023 after undergoing knee surgery.
Chelsea coughed up a £36m fee to prise Ziyech away from Ajax in the summer of 2020, and the attacker has amassed 14 goals and 10 assists in 83 outings for the Blues since.
Ziyech has won the Champions League, Club World Cup and UEFA Super Cup with the West London club, but he only started 14 Premier League games in the 2021-22 season.
Tuchel has already allowed Romelu Lukaku to rejoin Inter Milan on loan this summer, while Christian Pulisic and Timo Werner could also be allowed to leave before the window slams shut.
A deal to bring Raheem Sterling to the club from Manchester City is thought to be edging closer to completion, but Leeds United's Raphinha is still favouring a move to Barcelona, in spite of a fee close to £60m being agreed with the Blues.