Managers have come and gone at Celtic Park, titles have been won and lost, and frequently the club have even proudly boasted the best defensive record in the land, but the one constant at Parkhead in the recent past has been a low rumble that the chemistry in central defence hasn't been quite right.
Bolstering the backline has been an unhappy and unfulfilled strategic priority during pretty much every transfer window for the best part of five years in the East End of Glasgow, but hopes are high that a solution may have finally presented itself.
For all the credit which has quite correctly been heaped upon goalkeeper Fraser Forster in the last month or so, it is also worth recording the fact that Efe Ambrose and Kelvin Wilson have started the last five matches together. These games have resulted in three straight clean sheets in comfortable SPL wins and a couple of Champions League outings in which the club recorded a first away group stage victory in Moscow, then lose narrowly at Camp Nou.
That it should be this particular pairing who have provided the foundation to the club's Champions League adventures was an outlandish thought as recently as the summer. You may recall that the club's initial central defensive target was Leicester's Matt Mills – the player eventually moved to Bolton Wanderers – and for much of the close season it seemed as though Wilson, after a shaky and injury affected opening season at the club, would be moving on.
The 27-year-old was linked with a switch to Ipswich Town, in return for a cut price £250,000 and with him having appeared ill at ease for much of a campaign which caused him to spend the period from September to December in the treatment room recuperating from a troublesome Achilles tendon injury, few supporters seemed inclined to mourn his departure. Whisper it, but with Charlie Mulgrew and Thomas Rogne both ahead of him in the pecking order, some may even have been keener to dispense with his services and keep hold of either Daniel Majstorovic or Glenn Loovens.
Thankfully, however, for both club and player – Ipswich manager Paul Jewell parted company with the south coast club this week – the proposed deal fell through. Wilson may not be getting mentioned for an England call like his club colleagues Forster and Gary Hooper just yet, but after looking nervous and clumsy during his opening Champions League match against Benfica, where he was partnered by Mikael Lustig, his recent displays have rehabilitated him in the eyes of the support. Like Georgios Samaras before him, Wilson is proof of the benefits of a consecutive sequence of matches.
Forecasting great things from Ambrose this summer also required something of a leap of faith, even if it was one the club were fully prepared to make. Although the 6ft 3in Nigerian, who was recruited from Israeli side FC Ashdod in a £1.5m deal after the club guaranteed their place in the Champions League group stages, had been in at Manchester City's Carrington training complex for a trial, many are the exotic talents who have struggled to come to terms with the rough and tumble nature of the Scottish game. Particularly those who have reached the age of 24 without troubling any of the biggest clubs or biggest leagues in Europe.
But dig deeper and the player's pedigree undoubtedly is there. The man who tried so manfully to keep out Lionel Messi in midweek had actually come up against the Argentine before, in the gold medal match of the Olympic football competition in the national stadium in Beijing back in 2008. The Nigerian didn't actually make it off the bench in the final, in which an Argentina side featuring Messi and Sergio Aguero took gold courtesy of a goal by future Real Madrid player Angel di Maria but he made his mark on the competition – featuring alongside Everton's Victor Anichebe and West Bromwich Albion's Peter Odemwingie – and recently confirmed his importance to his country when he scored as Nigeria booked their place at this year's Africa Cup of Nations.
Ambrose was likened to Manchester City's Yaya Toure after his debut in midfield in a Scottish Communities League Cup tie against Raith Rovers, but so far Neil Lennon has been wise to use him in the Kolo role. His pace, reading of the game and composure in possession have made him a genuine asset to the Parkhead backline, even if such abilities don't always get as much prominence as the acrobatic, somersaulting celebration which greeted his maiden goal for the club in the 5-0 victory against St Mirren.
Disruption to the back four will come soon enough. Ambrose will jet out in January for the month-long Africa Cup of Nations and Lennon is likely to freshen things up for the upcoming challenges against Kilmarnock in the SPL and St Johnstone in the Scottish Communities League Cup. The defence will continue to have their work cut out at times in the Champions League, a competition where their share of possession (35%) is the lowest in the tournament. But for now the Parkhead club appear to have stumbled upon a settled, partnership at the back. For once, their fans might not need to have a new centre-half on their Christmas wish-list.