United were leading 3-2 heading into injury time at Old Trafford on Saturday.
But the Red Devils gave away a late free-kick, and their defending was all over the place as the ball was launched into the box for Dominic Calvert-Lewin to poke home.
The draw meant Ole Gunnar Solskjaer’s side missed the chance to go level on points with Manchester City, who extended their lead to five points the following day with a sensational 4-1 win away to Liverpool.
And while United remain second in the table, Ferdinand believes they can kiss goodbye to chances of a first league crown in eight years.
“You can’t defend it. At the end of the day Man United were sitting pretty at the top of the league,” said the Old Trafford legend on his Rio Ferdinand Presents FIVE podcast.
“We didn’t come into this season expecting to be title challengers. We were too far behind Liverpool. You can’t expect to have a turnaround that big to win the league, it’s impossible.
“But I’m like all the other fans. You see the league table, you look at the results, you get excited. When you put yourself in that position, Man United have to strike. You’re there now and there’s an opportunity.
“When there’s an opportunity, you’ve got to go. The problem is we’ve let this opportunity slip through our hands.”
United have won just two of their last six Premier League games, which included a shock defeat to Sheffield United and 0-0 draws against Arsenal and out-of-form Liverpool.
City, by contrast, have won their last nine league games in a row, and are unbeaten in 13 top-flight matches.
“You can see Man City with their experience, they’ve smelt blood, they’ve put their heads down, they’ve gone,” said Ferdinand, who won six Premier League titles with United.
“But United have stuttered, we’ve got the choke going, haven’t got it quite working properly. We have choked – it’s simple as that.
“I’d put us out of the title challenge unless we go on a run and we change our habits and our lack of consistency.
“But I haven’t seen enough to suggest we can go on a ten, 15-game winning streak. We’re tripping ourselves up all the time. It’s top four – we’ll finish second or third.”
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