The certainty is that they will be even stronger as the season progresses.
Neil Lennon, the Celtic manager, dismissed any notion of fielding less than a full-strength side in the fourth-round replay at Gayfield tonight and also indicated that Scott Brown will be allowed to run and run, and that James Forrest, Paddy McCourt and the troubled Anthony Stokes are slowly returning to fitness.
The display against Kilmarnock on Saturday showed Celtic are ready to park European ambitions while driving for domestic honours. A significant lead has been taken in the Clydesdale Bank Premier League, Celtic are in the semi-finals of the Scottish Communities League Cup and Arbroath now stand in the way of a fifth-round place in the Scottish Cup.
"It will be Arbroath's cup final, it will be a full house and they will be hoping we do not turn up with the right sort of attitude," said Lennon. The manager, though, is confident that his team is up to the trials of Gayfield. "We will be very strong," he said of his team selection. "Players want to keep playing, they are in a match rhythm, in good condition. They are mentally in a good place and they just want to keep playing."
The manager was enthused by the 3-1 victory over Kilmarnock at Rugby Park on Saturday.
"I thought we were terrific and that is exactly the reaction I was looking for after the Spartak match," he said of Celtic's progress in the Champions League. "Psychologically, getting through has eased them, has given them something to look forward to in the New Year."
He was blunt about his specialist knowledge of Gayfield. What did he know of the scene of Celtic's latest big match?
"Nothing. It is by the coast so I would imagine at this time of the year it would be warmer. The pitch is in good condition from what I can gather. I think you need the right attitude and to be ready for a fight," he said of the priority for his players. It is not going to be like an SPL game or a Champions League game. They use a different kind of ball and we do not know what the conditions are going to be like on the night or how the conditions will play out so we may have to change our way of play at times to accommodate the conditions.''
It is a relief to Lennon that his captain will be available to play. The Scott Brown Injury Mystery has baffled some and bored others, including the central character.
The midfielder was in irrepressible form at the weekend but took umbrage at questions about the specifics of his injury and its treatment. Lennon believes his player is looking better after a period of great discomfort. He is also minded to let him play on until the summer. "We thought it would deteriorate rather than improve," said the manager of his player's hip injury. "Surgery is the last resort and is not 100% guaranteed to remedy the problem. If we can avoid it, great. We will shut him down at the end of the season and give him enough rest to recuperate fully.''
The importance of Brown to the team was shown emphatically at Rugby Park. "He was at the heart of everything that was good about the performance and he is a real leader," said Lennon. "To lose him at any time is difficult because he is such a presence in the dressing room and on the pitch but I am delighted with how things have turned around.''
Brown's reluctance to discuss the injury post-match included the denial of having an injection recently but Lennon said: "He has had an injection but maybe he does not want to talk about it. He would rather people were talking about his level of play. He is sick of the whole thing and would rather people talk about his football and not use the injury if he has a below-par game.
"There is no doubt it was affecting him – you could see it in Barcelona and at Benfica. But when Scott is in full flow, he is really strong and a good athlete.''
Brown may be given some respite tonight but Lennon has reinforcements at hand as Joe Ledley needs to rest for 10 days. McCourt started training yesterday, Forrest will be back in harness on Monday and Stokes will be making his first strides since July in about "three to four weeks".
A break beckons for Celtic, too, as a trip to the sun is planned. To avoid confusion, this is scheduled for January; not Gayfield tonight.