Big test for boss and players in Dortmund
This is a huge test for Jurgen Klopp and Liverpool. They won't play a better team than Borussia Dortmund all season and if they can somehow come through it in one piece, it would make a very important statement.
That said, I'm not very optimistic. Dortmund absolutely hammered Spurs in the last round and Liverpool trail Mauricio Pochettino's team by a very substantial 17 points, so the gap is obvious.
Realistically, this is Liverpool's last hope of featuring in the Champions League next season and they are coming up against a team which will be in the draw as Bundesliga runners-up.
They are not quite in the same class as Bayern Munich or Barcelona but this Dortmund team is back-boned by men Klopp hand-picked over years at the club.
They are World Cup winners and seasoned internationals and they are five points behind a very, very good Bayern team under Pep Guardiola and a remarkable 19 ahead of third-placed Hertha Berlin.
They have won 14 out of the last 16 games played and drew the other two - both 0-0 draws against Hertha and Munich. They are formidable and will be very hard to beat.
The up side, of course, is that Klopp knows every nook and cranny of the Westfalenstadion and the players who play there and nobody is better placed to find a weakness or two.
He watched most of them every day on a training ground, month after month, year after year and I'm certain, was able to give some very fine detail to his players during preparations for this Europa League quarter-final.
It will be a very odd night indeed for the Liverpool players. They will be used to hostility in away grounds but I think the Dortmund fans will give Klopp a very warm welcome and turn the event into a bit of a party.
It's their way. They create a remarkable atmosphere but any time I've been there, I wouldn't say it was hostile or intimidating in any way.
In fact, my only thought when I went there first was that I would love to play in front of these supporters.
That should be the response from the Liverpool lads but the jury is out on whether Klopp has really succeeded in removing the fear from their psyche so that they can face into a big challenge like this with a smile on their faces rather than worry in their minds.
He has made some progress but even in recent games, I've seen signs that he hasn't fully eradicated this failure of belief. It may well be that new blood is the only fix for the problem.
Klopp has been fortunate with the way this season has unfolded. There are bigger stories around than Liverpool languishing in mid-table and not really involved in any of the meatier stuff near the top of the table.
His personality and refreshingly open approach to his job captured a lot of the early headlines when he first took on the job but he has been able to continue his working assessment of the squad he inherited in relatively calm surroundings.
The Kop knows the story and knows that it will be one or possibly two summers before they can form a fair judgement about their new manager.
Until then, we can only hope that there is enough in the players he has to pull off what I think would be a major shock and win a place in the Europa League semi-finals.
At that point, Liverpool would become tournament favourites which would ask even more serious questions of some players who fell apart when they were chasing a title, dropped another notch when Luis Suarez left and looked like a hollowed out shell when Steven Gerrard moved to LA.
At the very worst and if things go wrong, it will give Klopp a very good idea of the quality he needs to bring in to be able to mix it with teams like Borussia Dortmund.
It will also give him a a chance to have a chat with some of his former players and maybe offer a few of them a job.
If his summer transfer list includes some of the lads who will be trying to beat Liverpool tonight, I wouldn't have a problem with that at all.