Marseille chairman Vincent Labrune has questioned the reasons given by Marcelo Bielsa for his shock resignation as the club's coach.
Following an off-season of speculation over his position, with a contract extension remaining unsigned, Bielsa returned to the club and led them in their opening Ligue 1 game on Saturday.
But following a poor 1-0 home defeat to Caen, the Argentinian used his post-match news conference to announce his resignation.
In a letter to Labrune, delivered just before the conference and made public on Sunday, Bielsa claimed his shock departure was due to proposed changes to his new contract stemming from a meeting last Wednesday with the club's director general, Philippe Perez, and a lawyer representing owner Margarita Louis-Dreyfus.
Labrune was not present at the meeting as he instead held talks with Napoli over a prospective signing, reported to be Holland midfielder Jonathan de Guzman.
But in a 25-minute conference at the club's training ground, he addressed the issues stemming from Bielsa's exit and the search for his successor.
"The main terms of the contract discussed at the end of April have not changed,'' he said.
"The owner made a big effort in mid-June and we had an agreement. It would have been a record contract [for a Marseille coach] but on Wednesday, Marcelo Bielsa changed the conditions regarding the option for an extra season.
"In the original contract signed last year, there was an option linked to a condition [finishing in the top three] but he wanted to remove that and his contract would have been for two years. That changed things but the same night, it was resolved. It was only a detail.
"He used that as a pretext to justify his resignation. He had made his decision before Wednesday, in my opinion.''
Perez, seated alongside Labrune, added: "Wednesday's meeting went very well. We discussed seven or eight points he wished to modify.
"I was as surprised as anyone by his resignation and the reasons he gave.''
Labrune praised Bielsa's impact in his one-year reign, which saw Marseille lead Ligue 1 for much of the first half of last season before fading to finish fourth.
But he revealed he had not attempted to talk the eccentric coach out of his resignation.
"Once his decision is made, he never goes back,'' said Labrune. "It would be impossible to get him to change his mind.
"Marcelo Bielsa brought us a lot in terms of increasing our intensity and professionalism. That is a big plus for the club in the years ahead. His tenure was a good thing for OM.
"We had a spectacular season but we did not achieve the objective of Champions League qualification.''
Franck Passi is leading the team on an interim basis and Labrune began the conference by stating that he would not be announcing the name of Bielsa's permanent replacement.
He later added: "We have complete confidence in Franck Passi, who will lead the group at Reims.
"Regarding a successor, we are not in a rush, we will work on it with complete discretion and take our time.
"We are looking for a coach who can continue the work of Bielsa and someone capable of adapting to the aims and ambitions of the club. We are looking for someone capable of using an attacking style of play.
"We need a coach who can come with two or three members of staff to replace those who left with Marcelo.''
One man linked with the vacancy, Jorge Sampaoli, is staying as coach of Chile according to reports in that country.