Despite lengthy talks with Borussia Dortmund over Jadon Sancho, United have struggled to land their top target and have only brought in one new addition in the form of Donny van de Beek from Ajax.
But Ferdinand feels there are a number of holes in the squad, both in attack and defence, and has particularly highlighted the importance of bringing in a pacey centre-back.
Asked if United still need to strengthen multiple positions, Ferdinand told BBC 5Live: ‘Yeah, I would say definitely after Van de Beek they need probably – if they’re going to really compete – three or four.
‘Players that can go in and actually affect the first team, the first XI.
‘And [Sergio] Reguilon we’re talking about, the lad at Sevilla who’s from Real Madrid, he was voted the best left-back in La Liga so really good credentials.
‘Luke Shaw I think is unfortunate in terms of his injuries. He’s played games but then he hasn’t been able to sustain a full season without any injuries, which is disappointing.
‘And then I think a centre-back. That area, for me, is where there’s a lack of real, genuine pace and I think the best teams around at the moment have a player in one of the two players that play [at centre-back] in a four that has genuine pace normally.
‘I think Liverpool are the team that’s dominated this season. The two centre-backs can be sat on the halfway line, they’re sitting there purring, waiting to be taken on in a foot race back to the goal and they back themselves.
‘And with that, what that does as well, it’s not just about pace – knowing how to defend as well – but what that allows is more players to be able to go forward and pin the other team back in the opposing team’s third, which is, the way the game is played today, very critical.’