Ahead of the hotly anticipated Europa League quarter-final, we look at the five major talking points which could be prove key factors in determining the winner of this week's first leg.
1. Where are Liverpool's goals coming from?
The fact that Liverpool's top two goalscorer's this season are midfielders is an unsettling statistic for Jurgen Klopp. Pair that with the fact that no player has managed to break into double figures for the season and it really does make for uneasy reading.
Daniel Sturridge's injuries have kept him out of contention for a long time but even when fit he hasn't quite been able to recreate the blistering pace and clinical finishing that made him one of the most effective strikers in the 2014-15 season.
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Meanwhile, Christian Benteke is still seeing more of the bench that the back of the net. The ex-Aston Villa forward is seemingly out of favour with Klopp, who has, more often than not, opted for another Belgian in the shape of promising young striker Divock Origi.
To add insult to injury, quite literally, Benteke damaged ligaments in his knee while on international duty with Belgium and will be out of action for at least four weeks.
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Roberto Firmino and Phillipe Coutinho have shouldered the goal scoring responsibility this season with 15 goals between them but without a sharp tip to the sword, Liverpool are bound to struggle to threaten a composed and rigid Dortmund back line.
2. Klopp returns to former club
"A story that only football could write" was the characteristically quippy response given by Klopp when asked about his reaction to being drawn against his former side. A positive reaction from a perennially positive man, but you can't imagine he will be overjoyed at the prospect of taking his Liverpool side, still unfinished and staffed with players recruited by the previous manager, to face a Dortmund side that, after being built by Klopp has been polished by new boss Thomas Tuchel and looked dazzling in their 5-1 demolition of Tottenham a few weeks ago.
Liverpool fans have reason to be optimistic, however. While Klopp recruited many of the players at Dortmund that have since gone on to be among the world's best, they are players he coached every day and will be well aware of their weaknesses and limitations. Insider information that could be invaluable in his strategy and approach to the tie.
Win or lose it will be an electric atmosphere, both in the Westfalenstadion and a week later at Anfield, something that a manager like Klopp revels in.
3. Mats Hummels and Ilkay Gundogan both back from injury
Steven Gerrard's Instagram post last year, showing the line up for a Champions League match in 2009, with the caption "Spine" highlighted what he, and others, believe is one of Liverpool's biggest problems.
Lacking a solid bedrock of talent is not something Dortmund have a problem with and following the return of two of their stalwarts, they will pose even more of a potent threat.
Mats Hummels and Ilkay Gundogan are back in training this week after suffering from a calf strain and foot injury respectively. The return of their captain and star centre-back, as well as a midfield orchestrator, will be a great boost for Tuchel and Dortmund at a time when Liverpool are struggling with an ever-growing injury list.
4. Tuchel has taken Klopp's side and added a new dynamic
Klopp's remodelling of Dortmund was drastic. In his time at the club, he shipped out 81 players and recruited 83, won the Bundesliga, the German Cup and even took them to a Champions League final. He imposed a strict training regime on the players and made them into a side known for its pace and athleticism, as well as "gegenpressing", Klopp's own brand of high intensity, high line football. He brought in players who are now household names and did it with plenty of change to spare.
A tough act to follow, but a young manager with a similar back story is going to give Klopp a run for his money if early indications are to go by.
Tuchel - like Klopp - was a great success at Mainz before signing for Dortmund. An ex-youth team coach who took the first team to the Europa League for the first time in ten years. Since joining Dortmund, Tuchel has a staggering 78% win percentage and has further developed the side's characteristic approach to the game.
His preference for an aggressive, pacey and counter-attacking style of play as well as some successful acquisitions in the transfer market have only added to the reputation of the 42-year-old, who looks set to become a household name himself if their form continues.
5. Five Liverpool players on the brink of suspension
Liverpool will be hoping on Thursday that they leave Dortmund with a crucial away goal or better yet, a win, but there may well be a pretty sizeable spanner thrown into the works if the players aren't able to keep their discipline.
Five first team players are one booking away from missing the potentially critical return leg at Anfield a week later, something Klopp will have to ensure his players are aware of.
While Coutinho and Firmino, being attacking players, are probably less likely to fall foul of the referee, the other three (Dejan Lovren, Alberto Moreno and Nathaniel Clyne) will be crucial in defending against the unnerving pace of Marco Reus, Pierre-Emerick Aubameyang and co. and will find it very difficult to finish the game without mistiming at least one tackle.