Despite rebuilding efforts, Rangers still have plenty to learn from their bitter foes
This week, in Glasgow, the talk is of transition.
Principally, of how Neil Lennon has realigned Celtic since Brendan Rodgers' fractious departure, while, at Rangers, how Alfredo Morelos has overcome both grief and major uncertainties already in his young life.
Less than a decade after turning out for Deportivo Independiente Medellin, the journey which has taken Morelos to Rangers has been circuitous, edgy and ecstatic.
The fervour complementing tomorrow's Old Firm clash is understandably embraced by the 22-year-old, especially in view of a background of hardship in the northern Colombian town of Cerete. When Morelos made his full debut for Colombia, his neighbourhood was closed off, and big screens erected in anticipation of the latest step for a favourite son.
In this context, there's little surprise - without wishing to veer into immaterial, clunky Latin American stereotype - 'El Bufalo' is quite the street fighter. Becoming an Ibrox idol, via HJK Helsinki, hasn't been painless as Morelos admitted in a frank Rangers TV documentary on Thursday. Revelations on family, faith and the memory of his late sister fuels the single-mindedness.
With 29 goals this season, the striker, now on board until 2023, is intrinsic to Rangers. Yet Morelos is still to score against Celtic, a prickly statistic.
While this particular hex should end at some stage, in terms of facing Lennon's side tomorrow, Rangers' title quest has frittered away in self-imposed fashion.
Steven Gerrard's men drew level in the Premiership with Celts following, what appeared to be at the time, a hugely significant 1-0 December derby victory; a singularly powerful performance. Scott Brown, the Celtic captain, drew incredulity in his recollection, describing that day as a "slight slip-up". Unfortunately for Rangers, this proved to be a false dawn.
Costly draws since, allied to Celtic's scintillating form since the January winter break and Rodgers' exit notwithstanding, leaves interim Parkhead boss Lennon's task to be one of simple housekeeping.
Fortuitously for Celtic, Lennon was available to take over amid Rodgers' switch to Leicester City last month. While we are led to believe the Ulsterman has "mellowed" in comparison to his previous tenure in Glasgow's east end, the desire to both properly extinguish Rangers' fading title hopes and enhance his own audition for the top job on a permanent basis is as strong as ever.
When in charge earlier this season at Hibernian, Lennon was pointed in his praise for both Gerrard and Morelos, when assessing Rangers in their season of fundamental shake-up. Theirs is the kind of all-encompassing hunger he can objectively admire.
Celtic are not at full strength with Kieran Tierney struggling for fitness and the game is too early for Tom Rogic, their graceful axis. Still, Lennon expects determination, crucially, for 90 minutes, with winning goals coming late recently at Hearts and Dundee, through derby specialist Odsonne Edouard.
Moreover, James Forrest can hurt the Gers down their questionable left and the battle between Scott Sinclair and Rangers captain James Tavernier will further intrigue.
For Gerrard, midfield is a place he instinctively understands - and the Ibrox chief faces big decisions ahead of the Celtic Park test. Will he finally opt for Steven Davis, who has shown full match fitness and guile in recent Northern Ireland internationals?
Glen Kamara was excellent for Finland in midweek too and his neat recycling is essential in the heat.
Both Ross McCrorie and Scott Arfield supply the vigour necessary to obstruct Brown's ability to dictate, while Davis has proven experience in the fixture.
The luxury of choice, in theory.
Celtic's post-Rodgers response has been testimony to their impregnable desire. A 'treble treble' remains a captivating objective. Correctly, both managers, under no circumstances, will accept complacency.
However, for all Gerrard's hasty reconstructive work at Ibrox, tomorrow is not where Rangers' season will ultimately jolt. The Light Blues must examine their old rivals to appreciate the importance of negotiating workaday games. For a 10-point deficit is beyond even the intervention of a swaggering Morelos.