The 71-year-old spent over 26 years in charge of the Red Devils before announcing his retirement in May, but did not win his first league title with the club until his seventh season.
Sir Alex went on to win 13 championships despite an unspectacular start to his United career, but Moyes does not believe he will be given the same opportunity to prove his worth.
|9/4||Manchester United are 9/4 with bet365 to win the Premier League
“I don’t think in this day and age you would get that. I don’t think you can ever ask for time now.
“All you can ask is to be judged on how it goes. I don’t think time is something managers tend to get. It is a tough start.”
Although Moyes is aware of the need to make a quick start at Old Trafford and the massive expectations facing him, the 50-year-old says the club's owners, the Glazer family, have been hugely supportive.
“I’ve met them a couple of times,” said Moyes. “They’ve been brilliant. I met them in New York and here.
“They have given me a lot of confidence. The message has been ‘get on with the job, there’s no panic here, take your time, do things the way you want, there’s no great expectations, get on and do the job’.
“They’re not owners that interfere, they are low-key and they have been great in my conversations with them.”