Former United defender Neville was a member of Moyes’ coaching staff last term as they limped to a dismal seventh place finish in the Premier League just one year after being crowned champions in Alex Ferguson’s final season.
The 37-year-old, who played under Moyes at Everton, has since left Old Trafford following the arrival of Louis van Gaal as United’s new boss.
But that hasn’t stopped Neville reflecting on what went wrong during one of the worst season’s in United’s illustrious history.
“I’ve had sleepless nights thinking about what happened last year,” Neville told the BBC’s Test Match Special.
“There is part of me that thinks it was an impossible job to follow Sir Alex Ferguson.
“I think Louis van Gaal has an easier task now, following the man that followed Sir Alex Ferguson.
“It was a really difficult job for David Moyes and I think rather than blame him, there has to be collective responsibility taken throughout the whole club.
“Last year was a complete failure, and a disaster from my point of view.”
Moyes was sacked by United as soon as it became mathematically certain that they wouldn’t qualify for the Champions League and he has so far been unable to land a new job.
But Neville remains a fan of the Scot despite his United woe and believes he will bounce back when he returns to management.
“David Moyes is an outstanding manager and will go on to be one for another club – it just didn’t work out last season,” Neville added.