Liverpool manager Jurgen Klopp has been handed an untimely concern over Darwin Nunez ahead of Tuesday's Champions League last-16 first leg against holders Real Madrid at Anfield.
The Uruguayan attacker landed awkwardly on his shoulder during Saturday's Premier League win over Newcastle United, and despite training on Monday, his participation in Tuesday's game is not certain.
Klopp is already working without four confirmed absentees in Luis Diaz, Calvin Ramsay, Ibrahima Konate and Thiago Alcantara, and it remains to be seen if Arthur can make his long-awaited return to the squad from thigh surgery.
Should Nunez fail to make the cut, the fit-again pair of Diogo Jota and Roberto Firmino will go head-to-head for the chance to join Mohamed Salah and Cody Gakpo in the final third.
Such a difficult selection dilemma should hinge on whether Klopp opts to deploy Gakpo centrally or on the left, but the Dutchman experienced joy through the middle against Newcastle, so Jota may be preferred to Firmino out wide here.
Eighteen-year-old Stefan Bajcetic has been a silver lining in a troubled campaign for Liverpool, and the Spanish youngster has surely earned a start in the engine room alongside Jordan Henderson and Fabinho.
Trent Alexander-Arnold will miss the second leg at the Bernabeu if he is booked on Tuesday, but there is no chance of the right-back being demoted here, as Andrew Robertson also holds his place on the left.
Making his first start since recovering from a hamstring injury, Virgil van Dijk made some vital contributions to the staunch rearguard effort at St James' Park, and the towering Dutchman should complete an unchanged backline with Joe Gomez and Alisson Becker.
Liverpool possible starting lineup: Alisson; Alexander-Arnold, Gomez, Van Dijk, Robertson; Bajcetic, Fabinho, Henderson; Salah, Gakpo, Jota
> Click here to see how Real Madrid could line up for the first leg body check tags ::