Liverpool midfielder Pedro Chirivella is the player at the centre of an EFL investigation that could see the Reds kicked out of the Carabao Cup, it has been claimed.
The 22-year-old did not have the necessary international clearance to feature in Wednesday's 2-0 win at MK Dons, in which he came on as a substitute for Naby Keita in the 63rd minute, says the Mirror.
The 22-year-old signed for the Reds' academy from Valencia in 2013, and made his debut for the club in a 1-1 Europa League draw with Bordeaux in September 2015, when Brendan Rodgers was still the Reds' manager.
But Wednesday's appearance off the bench was his first outing for Liverpool's first-team since a 3-1 defeat at Swansea in May 2016.
Since then he's been on loan spells to Dutch sides Go Ahead Eagles and Willem II, as well as Extremadura in Spain in January last year.
However Chirivella ran into registration problems with the latter, and failed to make an appearance for the Segunda Division side before returning to Liverpool .
It is thought that he then needed fresh international clearance to feature for his parent club upon his return, with Liverpool having made an application on his behalf in July.
The Reds feel that the failure to register him is an administrative error from the FA, and are confident that they won't face expulsion from the Carabao Cup.