So far, the Parkhead support have already cost their club £190,000 in fines and that total looks set to grow after Europe’s governing body opened a fresh cash against the Scottish champions as a result of illicit banners being displayed against their Israeli opponents.
Andy Newport takes a look at the Hoops’ previous run-ins with disciplinary chiefs.
December 2011: Celtic are fined £12,700 by UEFA after fans make pro-IRA chants during a Europa League clash with Rennes in Glasgow.
March 2012: The Parkhead outfit are again punished with a £21,000 penalty after supporters set off fireworks and unveil an insulting banner aimed at UEFA during their Europa League fixture with Udinese at the Stadio Friuli in Italy.
September 2012: The use of fireworks at Celtic Park during a Champions League qualifier with Cliftonville costs the Scottish title winners another £4,200 as they are again found guilty of “improper supporter conduct”.
December 2013: A fourth fine of around £42,000 is issued to the club after the Green Brigade unveils “illicit” banners depicting IRA hunger striker Bobby Sands and Scottish historical figure William Wallace before Champions League group match with AC Milan.
September 2014: UEFA again cracks down on the Hoops, this time issuing a £15,900 fine after fans display a Palestinian flag during a Champions League qualifier against KR Reykjavik.
February 2015: Clashes between fans and Croatian police, as well as the use of fireworks during a Europa League group stage match against Dinamo Zagreb, sees Celtic receive a £7,300 bill from disciplinary bosses.
March 2015: Parkhead chiefs are given another £3,600 fine just a month later, this time after flares were set off by travelling supporters during a Europa League round of 32 clash with Inter Milan in the San Siro.
February 2016: The use of pyrotechnics again lands Celtic in trouble as they receive a £10,000 fine following a Europa League tie with Fenerbahce in Istanbul - although a portion of this is related to the “improper conduct” of the team.
August 2016: UEFA opens its latest disciplinary proceedings against the Scottish champions after hundreds of supporters display Palestine flags during their Champions League qualifier against Israeli side Hapoel Be’er Sheva. A hearing on September 22 will decide whether they are guilty of “illicit banner” charges.