Pako Ayestaran revealed he would not have accepted the job of Valencia head coach until Gary Neville had approved his appointment.
Ayestaran - who assisted Rafael Benitez with the La Liga club as well as Liverpool - was only drafted in to assist Neville in February, but has been elevated to the number one role following the former Manchester United defender's sacking.
At his unveiling on Thursday, the 53-year-old revealed he would not have accepted the promotion if Neville had not given the move his blessing.
"When Valencia offered me the role I just spoke about two conditions," he said.
"The first one was Gary Neville has to agree as I have said If Gary Neville didn't agree I wouldn't be seated here. The second was I have to bring in my own coaching team.
"I have always thought that my values are before everything. You can see in the papers that I have rejected many jobs because I gave my word to others before, so that was clear to me.
"When Valencia spoke to me about taking the bench, the condition I had in that moment was Gary Neville had to agree.
"I spoke to Gary and asked if the club has spoken to him and he said 'Yes, they have done' and told me 'Pako, this is football and that's it. The club doesn't want to change things drastically. They think you have to be the coach and I agree, so you don't have any problem of replacing me'.
"Even Valencia offered me to buy the tickets to Singapore [to visit owner Peter Lim] but until I had spoken to Gary I told the club not to buy anything.
"Gary did a huge amount of work and he gave everything for the club, but it wasn't enough.
"I am very happy coming in to a place where you can feel at home, where I was loved and we did great things [with Benitez], so I am really happy in this moment leading this project to the end of the season. The feeling is fantastic."
Ayestaran has opted to retain Gary's brother Phil in a coaching position and will face Las Palmas away on Saturday in his first fixture in charge, with Valencia only six points above the bottom three.