They are pursuing their own merits, and the suggestion that this Clydesdale Bank Premier League title might somehow be devalued because Rangers are not involved brings an affronted response. "This one may actually mean more," said Neil Lennon, the Celtic manager.
The title is not yet won but, with a 19-point lead, Celtic can be granted licence to begin to assess their campaign. It is a moot point, but the Rangers squad in its current form – given cup defeats by Inverness Caledonian Thistle and Dundee United – would be unlikely to challenge anyway. The dynamic of the Old Firm's enduring competition with each other has been the driving force of previous campaigns, but Celtic have been able to replace the rivalry with the elite competition of the Champions League.
Fans will not miss the old enmities when there have been games with Barcelona, Benfica, Spartak Moscow and Juventus to savour. For the players and coaching staff, too, reaching the last 16 of the Champions League has brought a series of challenges and situations to contend with that the campaign has felt more taxing, despite the comfortable lead in the title race.
"Rangers being out of the league doesn't take away any of the satisfaction, not for me or the players," Lennon said. "We won the league with Rangers in it last year. They're not here now and there is nothing we can do about that. The reality is that they're in the third division and we need to keep improving as a club, keep winning and keep creating assets in the squad. We've done that, more or less reaching all the targets we wanted to. Others may look at it differently, but you can only beat what's in front of you.
"Winning championships is not easy, even though everyone looked at this one as a foregone conclusion. But if you look at Germany, Bayern are 15 points clear. Manchester United are 12 points clear in England and I don't know how far ahead Barcelona are. Not many of the big leagues are competitive. They tend to have one dominant team and that seems to be the case with us as well."
There are still difficult opponents to overcome, but the absence of Rangers, or another legitimate title contender, has reduced the damage caused by dropped points. Celtic have 58 points this season, seven fewer than at the same stage in the last campaign. They were 14 points ahead of Rangers then, but had scored eight fewer goals than this year. In truth, the absence of a challenger has allowed Celtic breathing space, but the players have maintained their competitive standards to such an extent that their dominance of the league has long been established.
"I know they have a brilliant mentality," Lennon said of his players. "They keep surprising me, though. For such a young team, the experience they've gained in the last couple of years will stand them in good stead for wherever they go next. It's not easy playing here. It's not easy rising to the expectation at times, but they've handled it very well. They won't get the credit for it years down the line because people will say 'well, Rangers weren't here'. But they were here last year and our players coped very well with a huge deficit in the league. This season they've handled big games pretty well, too."
Two dropped points against St Johnstone on Tuesday night would have felt like a minor setback, but Lennon could dwell upon an impressive first-half performance that ought to have swept the Perth side away. He described the opening 45 minutes as the best football that he has seen his team play. Lennon will demand a certain level of self-motivation among his players, but he has also set points targets for his team and individual targets for individual players.
"You're expected to win all the time but it's hard to win games especially when teams face Celtic," said Kelvin Wilson, the Celtic defender. "For other teams it's their cup final against the champions. It's a great achievement to stay first. You play in Europe and face Barcelona in midweek and then have a league game on a Saturday. But you go into that league game with a lot having been taken from you both mentally and physically from the European match. That's why when we look back on this season it will be one to be proud of. Any season when you win a title you have to enjoy it."