Speaking to ESPN FC, former Chelsea and Scotland midfielder Craig Burley said: "Quite frankly, Ralf Rangnick was just out of his depth wasn't he? It became quite apparent early on that he was out of his depth.
"Now, there was a bit of everything going on here. There were underperforming players, there were leaks to the media, there was everything. But it was crystal clear that he had no solution on the field, nothing.
"There was nothing, absolutely nothing. And that's not down to players not being bothered, not after a couple of games, maybe after three or four months. The responsibility lies with the Manchester United board.
"So it was crystal clear Rangnick was out of his depth but just notch this on the board as one of the hundreds of bad decisions this club has made in the last eight or nine years since Sir Alex Ferguson left the club."
Rangnick was set to transition into a two-year consultancy role at Old Trafford at the end of his spell as Man United's interim manager this summer.
However, it was officially announced in late May that the German would be leaving the club for good to focus on his job as new Austria head coach.
