James Pearce - Midfield balance is the dilemma
Jurgen Klopp has got some huge decisions to make.
The biggest is whether he risks Roberto Firmino, who is desperate to be involved despite picking up a groin problem in training last week.
Firmino is so crucial to how Liverpool play and Klopp needs his "engine" out there at Camp Nou. Neither Daniel Sturridge nor Divock Origi provide the same qualities.
Joel Matip has to come in for Dejan Lovren in the back four after being rested against Huddersfield, while the real dilemma surrounds the balance of the midfield.
I think the emphasis will be on solidity and trying to deny Barca space to operate in. I'd go with the trio of Fabinho, Jordan Henderson and Gini Wijnaldum.
My team (4-3-3): Alisson, Alexander-Arnold, Matip, Van Dijk, Robertson, Fabinho, Henderson, Wijnaldum, Salah, Firmino, Mane.
Liverpool CEO Peter Moore sends message to fans in Barcelona after despicable video surfaces
Ian Doyle - Firmino simply has to start
It has become the biggest game in Liverpool's season - and there are a couple of big decisions for Jurgen Klopp to make ahead of the Camp Nou crunch.
Up front, it's all about Roberto Firmino's fitness. If the Brazilian is anywhere close to being available , as all the signs suggest, then he simply has to play and complete that fearsome attacking trio with Mohamed Salah and Sadio Mane.
Defensively, there have been some calls for Joe Gomez to replace Trent Alexander-Arnold at right-back and provide a bit more solidity with Barcelona likely to be more on the offensive in this first leg.
I'd resist that, and instead restore Joel Matip in place of Dejan Lovren at centre-back.Midfield, again, is the main poser.
It's harsh on the in-form Naby Keita, but he drops out, with James Milner also content with a place on the bench.
That means skipper Jordan Henderson and Fabinho are joined by Gini Wjnaldum, whose ability to keep the ball will be crucial.
My team (4-3-3): Alisson; Alexander-Arnold, Matip, Van Dijk, Robertson; Fabinho, Wijnaldum, Henderson; Salah, Firmino, Mane.
Connor Dunn - Alexander-Arnold over Gomez
The attacking prowess Liverpool possess is something that is rightly feared across Europe but that hinges on the prolific front-three all being fighting fit and ready to start.
So with that in mind Roberto Firmino is included after training at Melwood on Tuesday alongside Mohamed Salah and Sadio Mane. Then comes the midfield.
For his workrate Jordan Henderson must start, for his ball keeping ability Gini Wijnaldum joins him and to cope with excellent threat of Barcelona Fabinho also takes his place in a midfield three for defensive brilliance and forward thinking attitude.
Joel Matip should come back in for Dejan Lovren in the heart of defence alongside Virgil van Dijk and Andy Robertson unquestionably takes his place on the left.
For me Trent Alexander-Arnold stays in right-back too despite the school of defensive thought for Joe Gomez to assume that position.
My team (4-3-3): Alisson; Alexander-Arnold, Matip, Van Dijk, Robertson; Fabinho, Wijnaldum, Henderson; Salah, Firmino, Mane.
Theo Squires - Matip's spot is nailed down
While Barcelona defenders vs Liverpool attackers and other key battles that could decide Champions League semi-final first leg at times this season, they boast the planet’s greatest ever player and on their day they remain the best side in Europe.
With the first leg coming at Camp Nou, Liverpool need to remember they don’t need to get the job done tonight. Get an away goal and they are set up nicely for the return leg at Anfield.
Keeping that in mind, a more conservative approach would be wise. Philippe Coutinho will be desperate to impress against his former side and we all know what he can do cutting inside, so I’d start Joe Gomez at right-back in place of Trent Alexander-Arnold.
Joel Matip has nailed down that starting role alongside Virgil van Dijk so he comes back in for Dejan Lovren, with Andy Robertson making up the back four in front of Alisson.
The big talking point is Roberto Firmino’s fitness after sitting out Friday night’s clash with Huddersfield Town. If he’s available to train, he’s available to start - the Brazilian leads the line flanked, as always, by Sadio Mane and Mohamed Salah.
Meanwhile, Naby Keita is the unfortunate man to drop out of midfield. Fabinho is restored in the holding role with Jordan Henderson and Gini Wijnaldum making up the engine room trio.
Liverpool starting XI (4-3-3): Alisson; Gomez, Matip, Van Dijk, Robertson; Fabinho, Henderson, Wijnaldum; Salah, Firmino, Mane.
