Van den Berg is currently in his second stint at Preston, having played there on a six-month loan spell last season.
The teenager has been able to establish himself as a fixture under Frankie McAvoy at Deepdale, clocking up minutes as a right-back, right wing-back in addition to his natural centre-back role.
Rafferty, Van den Berg’s Lilywhite team-mate, rates him highly and lauded him as a beast on the pitch, highlighting his impressive physical qualities.
The 28-year-old added that the Reds loanee is technically good and insists he has all the attributes to develop into a top centre-back.
Asked what he thinks Van den Berg’s best qualities on the pitch are, Rafferty told LFC TV: “Physically he is a beast.
“He has got all the attributes.
“He is big, he is strong, he is powerful, he is quick.
“And not just that, technically really good.
“That is probably why Liverpool bought him.
“He eventually wants to be a centre-back and I think he has got all the attributes to be a centre-back.”
Van den Berg has started all but one of Preston’s Championship games so far this season and is again expected to feature at the weekend when they take on Blackpool at Bloomfield Road.