In order to reach the final of the Europa League, Liverpool have been set the task of overhauling a one-goal deficit against a solid and resolute Villarreal side who are aiming to move within just one match of winning their first European trophy.
Having looked reasonably comfortable at the back for long periods, it was a massive setback for Liverpool to concede a goal right in the dying seconds of the first leg when they were caught on the break thanks to an intricate counter-attacking move from the Spanish side, whose players and coaching staff celebrated as if they had already won the tie.
While a potentially significant goal, such euphoric scenes will have riled Liverpool and made them even more determined to prove a point and make the hyperactive maverick Marcelino seem foolishly premature in his delirium. Make no mistake, the Reds are still very much in with a shout and will know that in order to turn things around they may need to show patience in abundance, with Villarreal likely to set up with a defensive and organised mindset while attempting to strike a killer blow from a rare attack.
One thing that did stand out from the first leg was the amount of controlled possession that Villarreal allowed their opponents to have, and it has to be said that Liverpool did not make the most of it. Roberto Firmino saw his second half effort tipped on to a post, but too often there was a lack of end product as the final ball continually went astray, so that is clearly an area that Jurgen Klopp will look to ensure his side improve here.
Klopp also left El Madrigal with questions to answer as he refused to field striker Daniel Sturridge, leaving him on the bench and only bringing on fellow frontman Christian Benteke with just a couple of minutes of remaining. Villarreal may have been there for the taking, so it was a missed opportunity that the Reds will be keen not to regret when this one is over.
Last time Liverpool were involved in the semi-finals of the Europa League they lost to an away goal scored by Diego Forlan of Atletico Madrid back in 2010. They will hope not to suffer a similar fate at the hands of Spanish opponents, and after the manner in which they beat Borussia Dortmund in their quarter-final encounter, anything is possible regardless of how good a start they make.
Sturridge is likely to start this time for Liverpool, but Mamadou Sakho will not play again this season while midfielders Jordan Henderson and Emre Can remain injured. Despite that, Klopp will make a number of changes from the side that lost at Swansea City in the Premier League at the weekend.