The two sides meet in the Europa League on Thursday evening with a place in the semi-finals up for grabs.
The tie is finely balanced after they played out an entertaining 1-1 draw in Germany last week.
That game saw the Reds put in a highly impressive display against Jurgen Klopp’s old side, with the defence in particular claiming the plaudits.
Freund though, says that central defensive duo Lovren and Sakho are the weak links that his former side should target to secure victory at Anfield.
"A good start in the game would be very good," he told Sky Sports. "Dortmund should attack very early in the first ten minutes. They should try to force Liverpool to make mistakes.
"The central defenders of the Reds are the weakest links - Dejan Lovren and Mamadou Sakho. If they are under pressure, they make mistakes."
Unfortunately for Freund, the stats from the first game demonstrate that Lovren and Sakho may not be the weak leak he believes them to be.
The Croatian managed one tackle, two interceptions, two blocks and six ball recoveries in the game as well as eight clearances.
Sakho was similarly impressive, posting one tackle, two interceptions, three blocks and four clearances as well as eight recoveries in a top-notch display from both centre-halves.