Disgraced English rugby champions Saracens could be in big trouble again, this time in European competition.

The north London club, which was recently relegated from the English league for breaching salary-cap regulations, is facing a misconduct complaint by European Champions Cup officials for fielding an ineligible player in a crucial pool-stage match last month.

A hearing is taking place in London on Friday. Saracens could potentially lose its place in the quarter-finals.

Saracens is the defending English and European champion, and the continent’s most dominant club of this era, but is the subject of one of the most spectacular downfalls in the history of club rugby.

Less than 24 hours after its relegation from the English Premiership was confirmed for three seasons of spending above the cap, Saracens played Racing 92 in a European game on January 19 needing a victory to advance.

United States international Titi Lamositele was named in Saracens’ squad, and came on as a replacement in the 60th minute, but may have been ineligible because his work permit expired on January 18.

“This may have constituted a breach of the disciplinary rules,” tournament organiser European Professional Club Rugby said in a statement.

Saracens won the game 27-24, pushing Glasgow Warriors out of the final quarterfinal qualification spot.

A three-person panel will hear the misconduct complaint.