Marseille announced the departure of sporting director Andoni Zubizarreta amid uncertainty over head coach Andre Villas-Boas.
Ligue 1 outfit Marseille and Spaniard Zubizarreta parted ways by mutual consent, it was confirmed on Thursday.
Zubizarreta joined Marseille in 2016 and saw the club finish second in 2019-20 after the Ligue 1 campaign was ended prematurely due to the coronavirus pandemic.
The exit of Zubizarreta has now raised doubts over Villas-Boas, who has previously said he will not stay if Marseille cannot match his ambitions.
"I want to thank Frank McCourt, Jacques-Henri Eyraud and Rudi Garcia for their confidence in me," Zubizarreta said. "It was a great joy to participate in a project as important as this one with OM.
"Thanks to André Villas Boas for having delighted me with his football and for becoming a true friend. Thank you to all the sporting staff with Albert Valentin on the front line, for your professionalism and pride. And what can I say of my players? And you, OM supporters? Thank you, thank you very much.
"We shared a project in which we experienced great joys and dark days, but in which I fought every day to do the best possible for the club minute by minute, hour by hour, and day by day ... behind the scenes or in full light, always trying to give my best.
"It is the project, this club, this city that have been in my heart and in my brain 24/7, because when there is so much passion around a club, it requires as much passion on a personal level, with feelings and energy.
"Thank you all for your confidence and your ability to always go forward. In Basque we say: "amaya da asiera" - 'the end is the beginning'. I close the door as Sporting Director and I begin as an OM supporter."
Marseille president Jacques-Henri Eyraud added: "Andoni is the first leader I recruited at the start of our project. It is therefore with great emotion that we part ways today.
"Since 2016, he has been by my side in all our battles. He was fully dedicated to bringing OM back to the heights it should be held to, and he always brought his expertise as we rebuilt the foundations for both the first team and the academy.
"Andoni is an honest man with great integrity. Beyond his immense role, he is a high-quality professional with whom I will always have a lot of fun talking. "