It's the Scottish Premier League clash of the titans the fans have been waiting a long time to see. And we are not just talking about Celtic v Rangers.
There's also a fascinating sub-plot to the long-awaited return of the Old Firm derby in the Scottish top flight: namely Scott Brown v Joey Barton.
Ever since the ever-controversial Barton made his surprise move to Rangers in the summer; fans of both teams - and beyond - have been waiting for this one.
Barton and Brown sounds like a firm of solicitors, and we might well need one as two of the game's most aggressive competitors slug it out in the midfield warzone.
It has been suggested, in certain quarters, that serial offender Barton has mellowed since moving north of the border. A bad boy reformed.
Don't you believe it. When that first whistle blows it will be business as usual for the man signed from QPR. Brown will not be found wanting either.
Expect fireworks; tackles galore; fouls aplenty - and maybe the odd card of two!
The bookies, never one to miss a trick, are even taking odds on such things as who will be the first to get a big tackle in...who will get the first yellow card...who will be the first to take an early bath?
Both have already lit the green and blue touch paper with jibes against each other. Brown baiting Barton for, supposedly, being a Celtic fan, and Barton responding by tweeting a pic of a young Brown in a Rangers shirt.
There is possibly a mutual respect between two renowned midfield hard men, but that will be buried for 90 minutes or longer come Saturday lunchtime. The same time Jose Mourinho and Pep Guardiola will be going toe-to-toe at Old Trafford. Not quite the same thing, really.
Barton, who has already had a pop at Celtic boss Brendan Rodgers for his 'all-year round tan and white teeth', has now turned his attention to fellow midfield combatant Brown, insisting 'he's not even in my league'.
Quoted on the BBC Sport website the Rangers man, who has made more of an impact off the field than on thus far, added: "He's nowhere near the level of player I am. He can't get near me. If I play well, Brown doesn't stand a chance." Time for both men to put their muscle where their mouths are.
For the record, here's the tale of the tape as far as football's version of two prize fighters are concerned....
Age: Brown 31; Barton 34. Appearances: Brown 500; Barton 400. Red cards: Brown 6; Barton 9. We will watch and wait with interest to see if those final set of statistics remain at 6/9 come Saturday afternoon.
The time bomb is ticking, but who will come out on top in the battle of these midfield titans? You tell us.