Celtic suffered a chastening Champions League qualifying exit after leading 4-0 on aggregate against Austrian side Lask, only to collapse in the second leg and go out following a 5-1 defeat that took the tie into extra time. Manager Martin O'Neill admitted his side should have been "out of sight by half-time" but instead conceded a string of soft goals, prompting fierce criticism from Celtic figures including Chris Sutton, Kasper Schmeichel, Stiliyan Petrov and Neil Lennon, and adding to the club's reputation for European mishaps.

Celtic had taken the lead through Callum McGregor early in the second leg before Lask fought back to force extra time with a stoppage-time goal, then overwhelmed the Scottish champions. Unlike last season's exit, this collapse cannot be blamed on cautious transfer spending, as the club had invested £23m on new signings over the summer; instead, criticism has focused on the decision to sell key players Arne Engels and Daizen Maeda before European qualification was secured. The elimination could cost Celtic's owners up to £40m in lost Champions League revenue, with attention now turning to Saturday's domestic match against Falkirk.