Uefa's disciplinary body will review reports from officials at Celtic's Europa League game against Stuttgart on Thursday before deciding if any disciplinary action will be taken after the game was held up for more than three minutes when tennis balls were thrown on to the Celtic Park pitch.
Celtic went on to lose the game 4-1 and will travel to Germany for next Thursday's knockout play-off second leg.
After the match, manager Martin O'Neill criticised the throwing of the tennis balls.
Supporters have staged protests against Celtic's board in recent months, including some fans boycotting the Scottish Cup home win over Dundee.