(Reuters) - Celtic manager Brendan Rodgers was left with a conundrum on Tuesday when he was asked what he felt was the more believable -- the idea of the Loch Ness Monster existing or of Lionel Messi being human.
Messi or Nessie? Ultimately, Rodgers felt this jovial enquiry from a Spanish journalist on the eve of the Champions League match against Barcelona merited the equally jovial response: "That's the worst question I've ever been asked."
He knew what sort of headline the questioner was after, though. There is nothing mythical but something very monstrous about Messi's genius, as Rodgers found out in the Nou Camp in September when the great man's hat-trick decorated Barca's 7-0 win.
When the Argentine missed Barca's 0-0 draw at home to Malaga at the weekend with illness, Rodgers may have persuaded himself he would be spared the same torment in Glasgow, but it appears Messi will be ready for Wednesday's Celtic Park rematch.
"If he plays then he's arguably the world's best player," Rodgers conceded. "He's shown when he does play they are a different team."
After the Loch Ness Monster poser, the Celtic boss received an even thornier question: who should win the Ballon d'Or as the world's best player -- Messi or Real Madrid's Cristiano Ronaldo?
Ever the diplomat, he played a dead bat and, instead, threw in the name of the Barca striker whose career he once oversaw when he was Liverpool's manager.
"It's down to who you prefer, Messi or Ronaldo -- but I think (Luis) Suarez comes into that bracket as well now."
Celtic, who always seem to become a different team when fuelled by the fevered atmosphere of their Parkhead home, are warmed by the memory of their famous 2-1 triumph over Messi and Barca there in 2012.
This time, they simply must win to have any chance of qualifying for the knockout stages as they lie bottom of Group C, having eked out draws against Manchester City and Borussia Moenchengladbach.
"We showed them too much respect and the scoreline was bitterly disappointing at the time," Rodgers said, reflecting on the 7-0 humiliation.
"There were many aspects we learnt from, like being brave, and the players have shown they have learned from that.
"It was a tough game against a top-class, world-class team but I'd hope it will be a different performance from ourselves."
Celtic, with two points from four games, must overcome Barcelona and hope Manchester City fail to beat Borussia Moenchengladbach to stay in contention to reach the knockout stages.
(Reporting by Ian Chadband; Editing by Toby Davis)