Liverpool's quest for silverware this season takes them to the Nou Camp on Wednesday night.
Barcelona stand in their way as they chase a second consecutive Champions League final.
Let's take a look at some of the key clashes ahead of the first leg in Spain.
Messi vs Van Dijk
The newly-crowned PFA Player of the Year has shackled strikers all season long but this, without question, is his biggest challenge.
Van Dijk has played at the Camp Nou once, for Celtic in the 2013-14 group stage of the Champions League, and highlights of his impressive performance have been widely replayed on social media this week. The Netherlands captain has watched the compilation too, but admits a 6-1 defeat against a Barcelona side without Messi was a learning curve and not a fond memory.
Lionel Messi commands the spotlight and he is going to take Van Dijk out of his comfort zone. His double against Manchester United in the quarter-finals took him to 24 Champions League goals against English opposition – twice as many as any other players.
Ivan Rakitic vs Jordan Henderson
If there is no point trying to stop Messi, the key to being successful against Barcelona would be stopping the supply line to him, which Rakitic will aim to provide.
The last time Rakitic and Henderson crossed paths was in the World Cup semi-final in Moscow’s Luzhniki Stadium and the Croatia playmaker came out on top.
Liverpool’s captain, who will have support from Fabinho and Gini Wijnaldum, will need to smother Rakitic. It will be a fascinating battle.
Gerard Pique vs Mohamed Salah
It has been noticeable in recent weeks how Salah has roared back to form and he has scored many important goals.
This is the kind of stage he wants to command but Pique has been a master at this level for many years and knows every trick in the book.
Marcus Rashford, however, gave Pique difficulties in the quarter-finals and Salah will have studied the tapes to see what damage he can do as Liverpool seek a famous win.
Valverde vs Klopp
Ernesto Valverde already delivered a second LaLiga title in as many years, following on from last season’s league and cup double. But the 55-year-old’s often conservative style of play has not received universal praise from the Barca faithful, and there is no question he could use a Champions League title to strengthen his position. Valverde signed a one-year contract extension in February, but whether he gets another one may depend on their progress in Europe.
Delivering a style of play that pleases fans has not been a problem for Liverpool’s Jurgen Klopp, but the wait for silverware under the German is not over yet. There is every chance it will be within the next few weeks, however, which will only add to his already strong popularity on Merseyside and beyond.
tropicalda
462
I'm a hardcore Cule but I'm not really enthusiastic about Barcelona's chances against Liverpool. I really want them to win and I hope and pray that they do, but my brain isn't as firm in my hopes as my heart is. The primary fear of mine is the fact that Barca actually haven't faced a team at the peak of it's powers this season, especially in the UCL. They faced an Inter that's a shadow of it's former self and a Manchester United that's an excuse for a team. In La Liga, they faced a Real Madrid that has been substantially weakened post-Ronaldo, and more importantly, post-Zidane and an Atletico Madrid whose defence is crumbling, owing to the vagaries of time. So can Barca advance? Yes. But it's Liverpool that they have to beat and it's a Herculean task. But we've got a Hercules for the Herculean, haven't we? The little Hercules with the number 10 on his back... The only quality opposition they've faced were Tottenham and they were really convincing in their victory, as Messi ran riot in the away fixture and Dembele replicating the same at Camp Nou, But the problem here is that, Liverpool isn't Tottenham, Liverpool is Tottenham on steroids, and the kind of beast Barca is yet to encounter this season.
ArgentinaSeleccion
294
It's Messi vs Liverpool not van dijk.
VanishPrasad
226
The Van Dijk stats that make home the best defender of 2019. But can Messi dribble past this guy? Only time will tell.
SAUGAT_143
197
It's not between Messi and van dijik...do you really think one player can stop Messi? I don't think Liverpool will man mark Messi but they will sorrounds him by 3 players once he get the ball..It always happen when Messi is playing.not giving Messi to open will be their key tactics...If they give Messi little space he will make Liverpool great defenders look silly...
RazeTSKnightfury
143
Liverpool can only do it if they avoid this here 👇👇👇👇
batblpsu
134
alexsmirh
92
I want Messi to win this year champions league because he is the best player this season... it will be a big failure if after all the harp and praise singing to see that Barca didn't win this year champions league. It will be even a greater failure if Liverpool didn't win anything this season because as things are going now, you don't need a soothsayer to comprehend the handwriting on the wall...
Fulldosw
84
Well, I have been waiting for this moment, from now on I will become Shadow n will Vanished. Will come back next session with the same attitude
Rhapsody337
83
despite all said and done, barca should be the one careful, coz it's barca who'll be criticized heavily if they lose, Liverpool... well they haven't won anything recently so losing this wont be any different #barca ❤💙
Moomin17
82
Pique Will Definitely Stop The Front 3 of Liverpool Becuz he is 😊 THE MOST TALENTED ONE THE MOST DECISIVE ONE THE MOST DEFENSIVE ONE GERARD PIQUE FOR YOU 🙌
djawotwi11
78
Barcelona maybe the favourites but Liverpool are a very good team Liverpool have more points in the league than Barcelona and Liverpool are in the toughest league in the world
Trevorn
72
The main focus is pique and Van Dijik. Both center backs have been in fine form for their team. Now the real challenge has come to dictate which of the two deserves to be called best defender of the season. I personally think Pique will come good for Barca but not 100% convinced since he'll be defending against salah,mane and firmino. This match is one to watch, looking forward to it.
Chulbul48
69
Another Messi,s magic we will see this game 💕💕💕👌👌 #Forcabarca🔵🔴 🇳🇵
ChifuMu
66
THIS WILL DEFINITELY BE WORLD WAR 3. Barcelona assured the fans they will do everything in their power to win the UCL this season. The UCL could be Liverpool's only hope this season as winning the EPL is kind of tricky now. GAMES LIKE THESE ARE THE ONES THAT MAKE FOOTBALL THE BEST SPORT IN THE UNIVERSE.
Charmingboy
65
Nobody Can predict what will be result, but the result will come out who are strong on the pitch.
deeikp
61
This is an excellent game to watch because both teams like to possess the ball and with the high press high intensity of Liverpool. As good as Barca is, I think Liverpool has an edge because they went to the final last year and lost it because of mistakes they made. As a result, they spend a lot money to solve the problem
lukzlat910
41
The only way for Van Dijk to stop Messi now
hysonwayne
40
Welcome to Barcelona where we speak better on the pitch
Jaruhar009
37
I agree Dijk is the best defender now, but Messi has already dealt with Ramos & Varane, Bonnuci and Chiellini and many more. pair of best defenders) Is Dijk enough alone this time ? When Pepe man-marked Messi, he created goals for others because they left space to other players. Will be exciting to see tonight, Busquets or Messi who will be targeted by Klopp??
scofeeld
37
this is how Van Dijk will look at messi passing him today