Marcelo Bielsa has revealed why he quit as Lazio coach just two days after the Serie A outfit officially confirmed the Argentine would be taking charge in 2016-17. 

Bielsa was announced by Lazio on Wednesday as a permanent replacement for Stefano Pioli, who was sacked on April 3 following a 4-1 defeat to arch-rivals Roma.

However, a letter dated July 7 - published by various Argentine media outlets - shows why Bielsa refused to work in the Italian capita. 

The 60-year-old was disappointed that Lazio failed to sign any of their seven transfer targets, while he also lamented the exit of 18 players from last season.

"After four weeks working together with you, we could not sign any of the seven additions in the work program expressly approved by the President Claudio Lotito," Bielsa's statement read, written from his native Rosario in Argentina. 

"We also take into account the departure of 18 players who were involved in the previous season. 

"It was agreed as essential to the implementation of the work program that we would sign at least four footballers before July 5, with the objective that they would be able to participate in pre-season. 

"For my style of work we needed to have these players arrive in a timely manner to train."

Bielsa had been linked to the vacant coaching role left by Gerardo Martino at the Argentina national team, but he insisted in the statement that he did not leave for that reason.

"It is important to note I have no other alternative work offers," Bielsa - who coached Argentina between 1998 and 2004 - added. "We will send soon the legal documentation certifying the resignations. 

He concluded: "I understand that you inform this decision to the media. Only if necessary you may offer some kind of public clarification."