It could give us renewed enthusiasm.”It will be a shock and a significant blow to Celtic’s credibility if they do not progress to the Europa League knockout stages. Yet there are emotions ranging from anxiety to anger among supporters, who fear another window where Celtic are ponderous. “I’m sure Wilfried would have had a set of players that he was interested in,” O’Neill said. “That might be a different set of players to me and it might have been a different set of players to Brendan. “I don’t care who is going to manage this club, that’s what you aim for,” he said.