David Moyes has hit out at former club Manchester United for dismissing him before he could prove himself at Old Trafford.

Moyes replaced Sir Alex Ferguson last May, but lasted less than a year in the "impossible job" after being sacked in April for presiding over the club's worst season in the Premier League era.

The 51-year-old claimed that he was "devastated" to part company with the Red Devils, and remains convinced that he would have turned things around had United's hierarchy granted him more time.

"It was a step into the unknown and, looking back now, it was near enough the impossible job," the former Everton boss told reporters.

"I was devastated to lose the job because it was something I felt I could make a real success of. We knew it was going to take time to make the necessary changes. It was going to take time to evolve.

"But we were in the process of making other important changes. In the end, I don't feel I was given time to succeed or fail."

Louis van Gaal got his United career off to a losing start as the Premier League giants slumped to a 2-1 defeat to Swansea City - their first opening-day loss at home since 1972.