United have got off to a difficult start to the Premier League season winning just two of their opening four matches.
And Ferdinand is concerned about the about of goals they are shipping – especially the six at home to Tottenham.
“I think it’s a lack of the players being able to smell danger,” he said.
“When a player’s in a spot of bother or trouble it’s about stepping in and covering. And trying to reassure others on the pitch. It’s not been happening.
“I learnt over the years but these aren’t inexperienced players.”