Aldridge says Liverpool's back four lack protection from those ahead of them.
He wrote for the Liverpool Echo: "Plenty has been made of Liverpool’s remarkable victory at Newcastle United on Monday night. But for me there is one problem Arne Slot must address – and it isn’t necessarily the defence.
"The balance of the midfield isn’t quite right just yet. Yes, I know Liverpool have had players missing at the start of the season and they were without Alexis Mac Allister in the North East.
"But there’s a bit more to it than that. Part of the issue is Florian Wirtz has come in as the number 10 and is still adjusting to the physicality and pace of the Premier League.
"I’ve no worries about him getting used to it. He will. But he is much more of an attacking force than any of the players who featured in the role last season, and that’s putting more defensive pressure on the other two midfielders.
"Really, of those on the books, only Ryan Gravenberch and Wataru Endo could be deemed defensive-minded, although Mac Allister isn’t too bad in that regard.
"The worry for me is the defence isn’t being given the protection it needs, not least when up against a team who plays the long ball as much as Newcastle did."