Jamie Carragher has accused Manchester United of "mismanagement" over their transfers following their 5-3 defeat to Leicester City on Sunday.
United spent £200m this summer on the likes of Angel di Maria and Daley Blind but have now conceded eight goals in five games.
Carragher told Sky Sports News: "The bigger picture at United is that they're the biggest spenders in Europe and they didn't buy a defender.
"They weren't shocked that Ferdinand was going but they let him go, Vidic announced [he was leaving] in January.
"They're the biggest spenders – how have they not addressed that? To spend that much money and not bring in a top class defender - that's mismanagement."
United go to West Ham United on Saturday in their next league game.
