Former Celtic manager Martin O’Neill has publicly addressed the club's recent exit from the Champions League qualifying rounds, labeling the defeat as one of the most difficult experiences of his time at the helm. Celtic entered the second leg in Austria with a commanding 3-0 aggregate lead from the first match. The position appeared secure when Callum McGregor scored in the 21st minute, extending the aggregate lead to 4-0.

However, the match took an unexpected turn as Lask mounted a comeback, eventually winning 5-1 on the night after extra time. This result overturned the aggregate score and eliminated Celtic from the Champions League. As a consequence of the defeat, the club will now compete in the Europa League. Beyond the sporting disappointment, the loss carries significant financial implications, with reports estimating the club will miss out on at least £20 million in potential Champions League revenue. O’Neill, who managed the club for over 300 games, highlighted the collapse as a uniquely painful moment in the club's history.