The defending Premier League champions are languishing in seventh place and a staggering 18 points behind leaders Chelsea ahead of their clash against Aston Villa at Old Trafford.
I think it would have been a tough season for whoever was in charge of Manchester United this year
Ferguson led United to their 13th top-flight crown of his reign last May before earmarking former Everton manager Moyes as his successor in the hot seat at the Theatre of Dreams.
“If Sir Alex was here it would be difficult for him as well,” said Moyes.
“It could have been the case no matter what this season. But it has been so un-Man United, which is why we have to look to continue a policy of building, improving, getting better.”
United veterans Patrice Evra, Rio Ferdinand and Nemanja Vidic have suffered a noticeable dip in form over the course of the season, whilst Tom Cleverley and Marouane Fellaini have struggled in the Red Devils midfield.
And 50-year-old Moyes insisted the English champions were always going to have to rebuild this season.
He added: “People are aware there is a squad that is ageing, so I think it would have been a tough season for whoever was in charge of Manchester United this year.”
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