Peeters joined Liverpool from Feyenoord alongside Slot in June 2024 and has served as a central figure in the Dutch coach's backroom structure, responsible for the physical preparation and load management of the playing squad.
He published a statement on LinkedIn following Slot's departure.
"After two unforgettable seasons at Liverpool FC, it is time to say goodbye. Winning the Premier League together will always be a special memory and the ultimate highlight of this incredible journey.
"But above all, I'm grateful for two years of going to work every day with such enthusiasm, surrounded by amazing colleagues and great people.
"Thank you to everyone at Liverpool FC for the trust, support and unforgettable moments."
Peeters' exit is expected alongside that of several other members of Slot's coaching and support team, as incoming manager Andoni Iraola prepares to install his own staff. It is standard practice for a new manager's backroom team to replace all inherited positions.
Liverpool are aiming to have Iraola formally appointed before the World Cup begins on June 11. Formal talks opened on Sunday, with the club targeting a swift resolution given the scale of pre-season preparation work required — including a squad that has been significantly reshaped by the departures of Mohamed Salah, Andy Robertson and Ibrahima Konate.