Maccabi Haifa, The Israeli tchampions played an ineligible player in their second leg of the second qualifying round against FC Haka, which they won 4-0.
The player's name has not been released however a Liverpool spokesman confirmed they had been contacted by UEFA.
"We have been contacted by UEFA who have informed us that Maccabi Haifa are the subject of a disciplinary hearing tomorrow afternoon the outcome of which may have a bearing on the result of the Champions League qualifier against FC Haka,"