The former England and Liverpool Football Club centre half insisted that personnel isn't the only issue facing Liverpool's defence and even signing Virgil van Dijk - an obvious upgrade on what they have now - wouldn't make much of a difference.
Van Dijk is the Reds' priority target in the final weeks of the transfer window, with the Southampton centre-back having handed in a transfer request this week. "You want leaders and people to attack the ball".
"I think (Virgil) Van Dijk's agent has got another 20 grand a week on his contract", said Redknapp.
Carragher's colleague, Jamie Redknapp, then suggested Van Dijk could demand more money if he were to move to Liverpool following their defensive showing, to which Carragher replied: 'You talk about Van Dijk and yeah, he's a good player, but it comes from the sides of the pitch and the way Liverpool set up. What defenders can do it?
Watford defender Miguel Britos bagged a dramatic 93rd-minute equaliser for Watford, as Liverpool's defence crumbled under pressure. "He wouldn't be in Firmino's position (for the corner), he would have been in Lovren's or Matip's because they'd have been coming out of the team".
"Hopefully he'd make a difference on set-pieces, he's a bit taller, but if he was playing today instead or Lovren of Matip, he'd have been in their position".
'They play so high and wide that they have a centre-back exposed there all the time. They're bad defensively, one man won't change that.
"One man isn't going to improve [set-piece defending], that has got to come down to the manager", he added.
He said: 'There is a reason why they concede so many goals, because they are disorganised there and have no leaders at the back.
"I think Lukaku will get goals for them, especially in the games where they dropped points, at home against weaker opposition". The manager has been there 18 months now but there has been no change.
In the Sky Sports studio, Carragher and Jamie Redknapp weren't impressed with Liverpool's defending.
"We're still seeing the same things year in, year out, and it went back to Brendan Rodgers as well". The way Liverpool are set up - set piece wise - they will always concede goals.
"I think Manchester United will be in there, they didn't make the top four a year ago but I think they will with the additions that they've made", he said.