"This is their moment," said Neil Lennon yesterday. "They might never get this opportunity again.
"We have turned a lot of heads and the performances have shown the club are a force to be reckoned with again, but to really enhance the season and to put us back in that really big picture, we need qualification. That would justify all of it.
"There is the bar, they have set it, they know they can achieve it. What's stopping them from doing that? It's their time."
On the eve of his side's final group G Champions League game with Spartak Moscow at Celtic Park, Lennon was hitting the right notes. It was inspirational stuff, but then it has been an inspirational campaign. Lennon's challenge right now is to ensure his words ring louder in the heads of his players than the platitudes that have come their way ever since they beat Barcelona on a special evening at in Glasgow exactly four weeks ago. Even yesterday Lionel Messi and Carles Vilarrubi, the vice president of Barça, were talking up his side.
"The way they were in Barcelona after they had just lost in the way they did was amazing," said Messi. "Their fans deserve the knockout stages. I think the competition would be a quieter place without them." Vilarrubi called Celtic his second team. "I will be happy if they [Celtic] go to the second round."
Boxing off that match, when Celtic defeated Barcelona 2-1 on a truly historic night, cannot be easy. A result against Spartak tonight that betters what Benfica do against Barcelona, will ensure Celtic, the minnows of their group, go through to the final 16, for what would be the first time in five years. They could reach 10 points, which would be a club high.
Lennon has striker Gary Hooper, who missed the Barcelona game through injury, back, and his captain Scott Brown will also start, although the hugely influential Victor Wanyama will be missing in midfield through the yellow card he picked up late on in the defeat to Benfica in Lisbon. That narrow loss has moved Celtic's fate from their own hands but beating Barcelona in the Nou Camp is still a task of some magnitude, even with the home side set to rest half of their side tonight (although Messi will play).
"I think we've got to go for it," Lennon added. "I'm not going to put any extra pressure on them, I just want them to go and play as they can at home on a big European night, aggressively and with a good tempo.
"We have players who can score goals, and have flair players who can rise to the occasion. They are capable of doing it. Spartak are a dangerous team, but they haven't got the calibre of Barcelona or the structure of Benfica, the way they play, but they do have a lot of flair in their team as well.
"It would be my best achievement as a manager here. It would be great for everyone associated with the club and it would give the players something to look forward to and get their teeth into in the new year.
"No one gave us a prayer coming into the competition. There were people saying we wouldn't get a point and people saying we wouldn't get into the Europa League, but we felt that we had a decent chance and that's what we have given ourselves.
"However, regardless of the outcome, we will have European football [in the new year] and that was one of the targets going into the group. Which competition it is in remains to be seen but we would all love to be in the Champions League, obviously. I am not concerned with what other teams are doing in the competition. I am concerned with my own team and how they play, and regardless of whether Barcelona leave six players out, the six players who come in will be quality.
"What I want is for us to win the game and that would mean Benfica would have to win in Barcelona."
If the Champions League has unified Lennon's side, then their opponents are in disarray. Spaniard Unai Emery was sacked as coach following a heavy defeat to Dinamo 10 days ago. They have no form from their domestic league to bring into the game, and nothing to take out of it, regardless of what they do.
All focus may once again be on Barcelona, on how they are doing this time, rather than how they have done.
Kick-off Tonight, 7.45pm, Celtic Park
TV Sky Sports 3. Referee F Brych (Ger)
Odds Celtic 4-7 Draw 16-5 Spartak Moscow 9-2