Liverpool face Barcelona in their Champions League semi-final first leg on Wednesday, with Jurgen Klopp potentially facing a selection dilemma.
The next seven days could shape Klopp's legacy at Anfield but his decisions in terms of managing a squad as he tries to juggle a European and a pivotal Premier League clash just 72 hours later in Newcastle - live on Sky - should not be underestimated.
Jamie Carragher pondered last week: "The question of which tournament to prioritise has been shrugged off until now, Klopp deflecting the question by explaining the 'next game' is most important."
But, it is something that can be ignored no longer. If Liverpool can win at Newcastle on Saturday Night Football, they will return to the top, therefore piling the pressure back on to Manchester City for their clash with in-form Leicester on Monday Night Football.
The data shows that an away trip in a Champions League semi-final can affect the performance level in the next league game. Manchester United failed to win four of their seven league games following an away day European semi-final and Liverpool themselves were beaten 1-0 at Chelsea last season after travelling back from their second leg with Roma.
Liverpool have tended to struggle for intensity at times after a European midweek trip. As the table below shows, the Reds have struggled for goals, scoring just 17 in 11 games. That is an average of 1.5 goal per game which is well down on their usual average of 2.24 per game under Klopp in the last two seasons. Included in those 11 games is a 1-1 draw with Saturday's opponents Newcastle in 2017, where Liverpool lacked spark after a midweek trip to play Spartak Moscow.
So, should Klopp rest some of his stars with Saturday in mind? His major decision will regard his front three. Roberto Firmino missed last Friday's Premier League defeat of Huddersfield with what Klopp described as a "small muscle tear" - he is in the squad but can he be risked to play two emotionally and physically draining matches within 72 hours of each other?
And then there is Sadio Mane and Mohamed Salah, with 50 goals between them this season. Having at least one of them fully charged for Saturday makes sense - but resting them for a Champions League semi-final? Klopp wouldn't would he?
Analysis
Ahead of Wednesday night's game, Sky Sports take a look at three main talking points; whether Liverpool's former players will hurt them, why Jurgen Klopp two-legged knockout tie record is up there with the best, and just how Liverpool can find a weakness in the newly-crowned La Liga champions.
Gary Neville's view....
"Carragher summed it up on Friday Night Football saying if Manchester City dropped points at Burnley then Klopp would have prioritised the huge Newcastle game and leave two or three players out in Barcelona, as two wins would have made them champions.
"However, now City have won, Liverpool should play their best team in Barcelona as they've got a chance to get to a Champions League final against Tottenham or Ajax. The problem with that is you're asking Liverpool players - who don't look like they're tiring by the way - to go to the Nou Camp, which is a different level of mental and physical asks. They'll then have to deal with the travel back to Anfield and then play away on a Saturday evening in Newcastle. It's a tough ask.
"People will be thinking 'these players are on so much money - how can it be so difficult?' But even when I travel back from games now and get home at 3am, I don't feel quite right for the next 48 hours. And that's how footballers are but they are being asked to produce a physical job. Klopp should go full-strength in Barca."
Van Dijk keen to erase Nou Camp memory
Liverpool defender Virgil van Dijk wants to erase the memory of his only other appearance at the Nou Camp... a 6-1 defeat while at Celtic in December 2013.
"It is a nice stadium, an historic stadium and for me it was a great experience to play over there," he said. "It was my first time, my only time and my last time so far, so I am looking forward to playing them again, one of the best teams in the world, but I think this can be totally different than when I was there the last time."
Valverde: Unleash Messi!
Lionel Messi won the La Liga title for the 10th time in his 15 seasons with Barcelona on Saturday. He scored the decisive goal that allowed the team to clinch their eighth league title in 11 seasons.
"I've rested Lionel Messi more than usual but this has been a month with two Champions League clashes, and twice we had to play three games in a week," Barcelona coach Ernesto Valverde said
"We wanted to clinch the Spanish league title, but at the same time we also wanted to make sure he was prepared for this tie. I think I've probably got the balance right."
Klopp on Messi and Coutinho
Klopp rates Messi as the best footballer he has seen in his career, telling reporters: "I didn't see Pele live but there are a lot of good players. Lionel Messi is for me the best."
"Yes we miss Coutinho, a lot, because he is a world-class player and I loved working with him. But we had to deal without him and we really did well. When I first heard he wanted to go to Barcelona, I didn't imagine we could be that good [without him]."
Charlie's prediction
"We are into the Hollywood part of the tournament now, and these two will be favourites to lift the trophy whoever reaches the final. Barcelona clinched the title and Lionel Messi scored in a 30-minute cameo and was, crucially, rested. When you hear Messi speak about individual things you know he means business, and he has come out and said he wants the Champions League in his locker once more.
"This is a 50/50 tie in my eyes, though. When you go to the Camp Nou, you have to be cautious. When you go and attack teams, Liverpool's weakness, if there is a weakness, is their midfield. The instinct here is to say lots of goals. The defensive qualities of both teams have improved, so Liverpool will have to be patient, they are quite good at doing that. That said, I fancy Luis Suarez to get his first goal of the campaign against his old team to leave the tie wide open for the second leg."
CHARLIE PREDICTS: Barcelona 2-1 Liverpool (15/2 with Sky Bet)
Opta stats
- Liverpool are the only English side to win away at Barcelona in European competition, beating them 1-0 in the 1975/76 UEFA Cup and 2-1 in the 2006-07 Champions League.
- Barcelona have only progressed from one of their four European Cup/Champions league semi-finals against English opposition, having been knocked out in 1974/75 by Leeds United, 2007/08 by Man Utd and 2011/12 by Chelsea. Their only such progression came in 2008/09 against Chelsea, before beating Man Utd in the final in Rome.
- Barcelona are unbeaten in 31 Champions League home games (W28 D3), the best ever such run in the competition. The Catalan giants have conceded just 15 goals in those 31 games, and never more than once in a match.
- Barcelona's next goal in the Champions League will be their 500th strike in the competition; only Real Madrid (551) have scored more such goals than the Spanish champions.
- Barcelona's Lionel Messi has scored 24 goals in just 32 Champions League matches against English opposition, however the Argentine has failed to net in his two previous such appearances versus Liverpool.
When is the Champions League final?
The Champions League final, the 27th in its current format and 64th of Europe's elite-club competition, will take place on June 1, 2019.
Kick-off is at 8pm (BST), 9pm (CEST).
Follow Barcelona vs Liverpool in our dedicated live blog on the Sky Sports app and SkySports.com on Wednesday evening