But Ferguson’s men have been much-improved this season, with the Red Devils winning 14 of their 15 games at Old Trafford, while losing just twice on their travels.
“With Manchester City coming on to the scene in the last couple of years and Chelsea and Arsenal and Tottenham – teams that are vying for that top-four position – you would expect it would be really tight,” Ferguson told Sirius XM.
“After last season, what we said was, ‘Let’s make sure we don’t lose on goal difference’, because that’s what happened last year.
“Of course, our goal difference has improved dramatically, but I never thought for a minute we would be 15 points clear at this stage of the season.”
With most of United’s squad on international duty, Ferguson admitted he would be fretting over the fitness of his stars ahead of their trip to Sunderland in the Premier League on Saturday.
“Every coach in the country is praying that their players come back fit; that is the first thing,” he added.
“The fact that they have played last Friday and they have played tonight – we have a game at 12.30pm on Saturday away from home at Sunderland – so once I know later this evening how many minutes each player has played, I will start to think about my team for Saturday.
“I have to make sure I have some freshness in the team because we have Saturday lunchtime and then on Monday lunchtime we have Chelsea [in the FA Cup quarter-final replay], so it is a big ask for our squad and something that we really need to concentrate on and make sure we need to pick the right teams.”