Molby thinks the Reds' back-line has not been convincing with the Slovakian at the heart of it.
It was announced earlier in the week that Skrtel will be sidelined for six weeks with a hamstring injury that he picked up in the defeat to Watford on Sunday, which leaves the Reds a little on the short side when it comes to cover at the back.
The Slovakian, who was signed in 2008 by Rafa Benitez, has had several central defensive partners including Jamie Carragher, Daniel Agger, Dejan Lovren and Mamadou Sakho. During that time he has been part of a back-line that has been quite leaky and never looked altogether solid.
Molby wrote in his Liverpool Echo column: "He’s been in every big defensive partnership we’ve tried to form over the last few years but it’s never been entirely convincing.
"He’s a very aggressive player but on Sunday it almost looked like he was being bullied.
"He’s also not somebody who gives a lot of support to other players because he’s normally got enough on on his own."
Kolo Toure is tipped to take the place of Skrtel this weekend if Dejan Lovren is yet to fully recover from a knee injury that kept him sidelined for the defeat at Watford.
It is an interesting observation that Molby makes. Although Liverpool's defence has often been criticised, it tends to be whoever has partnered Skrtel who has borne the brunt of it. He and Daniel Agger used to receive quite a lot of praise despite the duo getting bullied by bigger strikers in the past - a lot like what happened in the 3-0 defeat to Watford on Sunday.
If Skrtel is out for a sustained period - with some suggesting he could miss as many as 11 games - then it will be interesting to see if a partnership of Dejan Lovren and Mamadou Sakho could end up flourishing. There have only been a couple of time when they have played with each other as a central defensive partnership, but on those occasions the Reds kept clean sheets.