The 40-year-old faced the wrath of furious fans after the team returned from the Nou Camp to their training base at Ciudad Deportiva de Paterna, while former Valencia goalkeeper Santiago Canizares demanded he resign.

The England coach vowed not to quit when asked directly in the post-match press conference, but the pressure is mounting and could reach breaking point with another defeat to relegation rivals Betis. Neville has failed to win any of his eight league matches since taking charge.

The former Manchester United defender insisted he had a “mechanism” for dealing with setbacks like the one suffered against Barcelona and said he last experienced doubts 18 years ago during his playing career.

“My positivity is immovable in life but when you have moments like this you don’t enjoy them at all,” he said.

“I felt helpless, trying to change things in some way but knowing the tide of the game was against us.

“That scoreline is unacceptable. The reality of me is that I last had doubts as a player 18 years ago and from that moment onwards I developed a mechanism to deal with moments like this.

“I’ve just said to the players in the changing room now, ’Forget (the defeat), everything in your mind now shifts to Betis’. Be absolutely clear, we have to deliver on Sunday.”

Canizares, who played for Valencia in two Champions League finals, was scathing of Neville, saying on Twitter: “I expected the coach’s resignation, as well as some apologies. I may be ignorant, but I’m surprised he hasn’t done it, I thought he was honest.”

Valencia go into the weekend five points above the bottom three and three clear of their opponents.