The club has had a stirring campaign so far and one result in particular made international headlines. Even that startling home victory over Barcelona will count for nought in terms of reaching the last 16, though, if the Catalans also lose their final Group G game at home to Benfica. The Portuguese are in second position and cannot be overtaken if they gain more points than Celtic in the final round of fixtures on December 5.
Some sobering analysis was inevitable around Parkhead yesterday after the club's second defeat in three European ties. It was suddenly chilling for them to see Benfica sitting second in the group table with only one round of fixtures left. In fact, Celtic still remain in a handsome position. A place in the last 16 is now a head-to-head contest between them and the Portuguese side and there is no confusion over which of them has the more formidable final game. No-one in their right mind would swap a home game against the group's bottom team with an away one against its leaders. So long as Celtic take more points at home to Spartak Moscow than Benfica do away to Barcelona, they will be in the draw for the Champions League knock-out round on December 20.
At first glance, a Barcelona victory looks as safe as houses. The four-time European champions have played 59 European ties at Camp Nou over the past 10 seasons, winning 45, drawing 10 and losing only four. In this context, the rare defeats are most relevant. Among the surprise setbacks were a 2009 group game against the Russians, Rubin Kazan, a last-16 leg against Liverpool in 2007, and a quarter-final against Juventus in 2003.
And then there is the night which might send a little shiver up Celtic spines. On December 9, 2009, Barcelona closed their group campaign with a Camp Nou fixture against Shakhtar Donetsk. They had already won the group and Shakhtar were certain to finish third whatever happened. Barca rested eight players, including Lionel Messi, and were beaten 3-2. The parallels between Shakhtar four years ago and Benfica now – two clubs of established Champions League pedigree – are obvious. Benfica may even be more dangerous given that, unlike the Ukrainian club, they head to Catalonia still with a chance of progressing in the tournament. What remains unknown is whether Tito Vilanova, Barcelona coach, will emulate his predecessor, Pep Guardiola, who had a habit of fielding a weaker team in their closing group match.
Neil Lennon isn't the type of manager who will simply sit on his hands hoping for Benfica to fall. No-one will be more aware than him of the dangers of taking victory for granted against Spartak Moscow. The Russians will finish bottom of the section but were seeded above Celtic when the draw was made and were 2-1 ahead against Barcelona after 78 minutes in Camp Nou before conceding a couple of late goals to lose 3-2. They won their home game against Benfica, which Celtic could not, and Uefa's Champions League statistics show that, compared to Celtic, they have had more possession (averages of 48 against 38%) and attempts on goal (44 against 37) in their respective five matches so far.
Naturally, the most revealing statistic of all is Celtic's seven points to Spartak's three. They have been more impressive than the Russians so far. No result can be taken for granted in the Champions League and Celtic could just as easily lose the match as win it, yet the inspirational lift they get from 60,000 supporters packing Parkhead has been obvious for years and the prize of a place in the last 16 will ensure another pulsating capacity crowd. Having guaranteed a finish in the top three in the section, there will be European football into the New Year and a place in the Europa League at the very least, but the club has impressively worked its way into a position which could bring a far bigger reward than that.
Financially, a win over Spartak would be worth £800,000 and a draw £400,000. There would be £2.18m from Uefa simply for reaching the last 16, plus the guarantee of at least one more full house and attendant commercial benefits. There aren't pound signs going through Lennon's head, though, and nor are his players consumed by anything other than proving themselves during the ongoing adventure of the club's first group campaign since 2008.
Of the four most influential players in their games so far, two will be missing against the Russians. Victor Wanyama is suspended and Scott Brown must surrender to surgery on the hip problem which has recently upset his career. The exceptional goalkeeping of Fraser Forster and Georgios Samaras' mature contributions in attack must be relied upon again. Gary Hooper and Tony Watt can also be matchwinners and it will not escape their attention that the 12 goals Spartak have conceded in the group so far is five more than the number let in by anyone else.
The events in Lisbon on Tuesday night often had the look of the old Celtic in Europe, taking a bit of a pummelling away from home but hanging on until they eventually succumb to endless pressure. There is no disgrace in losing away to Benfica, though, and, in general, this campaign has been about the emergence and growth of a set of Celtic players who had barely any previous Champions League experience between them. The home draw with Jorge Jesus' side was solid and then they drew enormous confidence from winning in Moscow and then competing so well in both games against Barcelona. Generally, they have looked comfortable in their new company.
Back when the draw was made in August, it looked like the story of Spartak Moscow's visit to Parkhead would be the return of a prodigal son, Aiden McGeady. An ankle injury may prevent him from being involved at all but, even if he is, the narrative is different now. It will be a night for transistor radios and smartphones, hoping to hear and read that the right result is unfolding in Catalonia. Celtic made much of their bond and friendship with Barcelona after the recent double-header. If they can take care of their own business at Parkhead, it will be down to their powerful pals do complete the job in Camp Nou a week on Wednesday.