UEFA has charged Maribor over crowd misbehaviour during their Europa League clash with Rangers on Thursday.
Steven Gerrard's men advanced to the playoff round of the Europa League after a 3-1 aggregate win following their 0-0 draw in Slovenia.
Maribor could face punishment over the use of fireworks by home supporters inside the Ljudski Stadion, while a second allegation relates to the throwing of objects.
Referee Jonathan Lardot had to stop play briefly during the second half while he collected a number of items that had landed around Gers keeper Allan McGregor as he prepared to take a goal kick.
Maribor's disciplinary case will be dealt with by the UEFA Control, Ethics and Disciplinary Body on September 27.
