The EFL is looking into whether Liverpool fielded an ineligible player in their EFL Cup third-round victory over MK Dons on Wednesday.
Reports emerged on Saturday suggesting an unnamed Reds player did not meet the registration criteria to feature in the competition.
An EFL spokesperson told Omnisport: "We are currently considering the matter."
Liverpool, who have been drawn to face Arsenal in the fourth round next month, could be fined or even expelled from the competition if they are found to have breached the rules, although the latter punishment appears unlikely.
In 2014, Sunderland were given a fine for playing Ji Dong-won in the EFL Cup and Premier League without full international clearance following a loan spell in Germany, citing an administrative error.
A Liverpool spokesperson told Omnisport: "The club are aware of a potential administrative issue pertaining to one of our players.
"We are working with the relevant authorities in order to establish the facts of the matter and will be making no further comment until this process is complete."
Liverpool started four teenagers against MK Dons as they recorded a 2-0 victory with a much-changed line-up.
