Spurs and Dortmund lock horns at Wembley in Wednesday night's Champions League last-16 first leg.
In this analysis, the retired Germany international shared what he feels are two major weaknesses in the Bundesliga side's team at present, one of which he insists will see them lose the game if they succumb to this issue.
According to BBC Sport, no team conceded fewer Champions League goals than Dortmund in this season's group stages, a tally of just two in six games, but their last two matches in all competitions have seen them ship six goals (Goal.com).
Freund, who made 115 appearances for Tottenham and 161 for Dortmund (Transfermarkt), noted how centre-backs Manuel Akanji and Dan-Axel Zagadou, who have been on form and improving this term, appear to be unavailable for the game in London.
"The biggest problem for Borussia Dortmund at the moment is the defence," the 49-year-old told the official Spurs website, also pointing out how midfielder Julian Weigl - now also injured - and former Mainz left-back Abdou Diallo have been drafted into central defence.
"In the last game against Hoffenheim they were 3-0 up but conceded three goals in the last 15 minutes. They completely lost their organisation, and that’s unusual for Borussia Dortmund. That shows they are not so well organised without the two regular centre-halves. Trust me, if they do that against Spurs, they will lose the game."
Freund also noted how Marco Reus is as influential to Dortmund as Harry Kane is to Mauricio Pochettino's side, adding that as another weakness which the Lilywhites could potentially exploit in the first leg.