Rashford has scored just eight goals in 36 appearances for United so far this season - a far cry from last term when he scored a career-best 30 goals for United.
He has also faced criticism over his off-field conduct. Reports in late January suggested Rashford had spent an evening at a Belfast nightclub before missing training with United.
And United manager Erik ten Hag branded Rashford's decision to go to a separate nightclub event after October's 3-0 derby defeat by Manchester City "unacceptable."
Former United defender Ferdinand feels Rashford, whose place in the England squad for Euro 2024 could now be at risk, should think about the people he surrounds himself with and perhaps think about moving away from Old Trafford.
"I think it's a pivotal moment in his career now, he's not a kid anymore," Ferdinand told Sky Bet's Stick to Football podcast. "I think there's a big decision to make, from him. He's got to look at who's around him, who are the external people? Are they the right people?
"Are they enabling him to make excuses for himself behind closed doors? Or are they saying 'look at yourself and be accountable for what you are doing'? He needs to look at that and own that and make big decisions."
The former England centre-back added: "When I left West Ham (for Leeds) I could have gone to Chelsea, that's probably a club I would have preferred to go to at the time. But the reason I went to Leeds was it was out of London and the external people around me, I needed to get away from.
"He might need to go 'you know what, I'll get rid of them and stay in Manchester, or I've got to leave Manchester and get rid of those people'."
Meanwhile, former United captain Roy Keane suggested a more old-fashioned approach would enable Rashford to contribute more to a Red Devils side currently 11 points adrift of the top four in the Premier League.
"A player can have an off spell or a dip, but he's certainly not enjoying his football," said Keane.
"The people around him, family, the manager, who's on his case every day? There's nothing wrong with the old-fashioned kick up the arse and going 'come on, we need more from you.'
"I don't think there's anybody on his case. But that doesn't mean he can't produce and start running a bit more."
