Cesare Prandelli "gave up" and resigned after demanding five January signings Valencia were unable to deliver, club officials have claimed.
Former Italy boss Prandelli abruptly quit on Friday after just three months in charge, leaving the struggling side 17th in LaLiga and in grave danger of relegation.
Los Che have endured a tumultuous 2016, Prandelli following Gary Neville and Pako Ayestaran in making a swift exit after being unable to improve the team's fortunes on the field.
Addressing the media on Saturday, senior club officials Anil Murthy and Jesus Garcia Pitarch claimed Prandelli walked away after being told the club were not capable of meeting his expectations in the transfer market.
And executive director Murthy, a representative of the club's increasingly unpopular Singaporean owner Peter Lim, made no secret of his displeasure at the Italian coach's decision to quit.
"I met Prandelli in Paterna 24 hours earlier, talking about signings in the winter market, so it was a big surprise to know that he decided to abandon the ship, a week before the market opened," he said.
"What do we do in this situation? Do we stop him, try to convince him? Given the delicate moment in which we are in I thought to try.
"But then I wondered what kind of person thinks a week before the market starts that the club can guarantee the arrival of five players over 26 years [of age]?
"How with so many years of experience can he not do anything to improve the performance of the [team]?
"He has decided that this challenge is not for him. He has given up. In short, he is a person who wants to leave and who looks for excuses to leave. Three months, six points - no need for excuses."
Sporting director Garcia Pitarch indicated interim boss Voro, who also took over following Ayestaran's exit and that of Neville's predecessor Nuno Espirito Santo, is likely to spend longer in charge this time around.
"The idea is that Voro will coach the team," he said.
"They [the club's owners] are not looking for a coach because they have not told me [to do so]."
Murthy added: "I have met with the players and I am optimistic with what I have seen, I admire Voro as a genuine and great professional."