As a Londoner, Mark Warburton is accustomed to making journeys accompanied by repeated warnings to “mind the gap.”

An Old Firm Hogmanay defeat for Rangers would extend Celtic’s lead at the top of the Premiership to 19 points, and with a game in hand it is not unreasonable to expect the unbeaten league leaders to soon widen that to 22.

The record winning margin – the biggest recorded in a European top flight – is the 29 Celtic streaked away by to win the title two years ago. A win at Ibrox and that will appear a breakable record for Brendan Rodgers. Warburton needs to mind the gap.

Both managers like to see themselves as being on a journey, insisting until they are blue – or green – in the face that they cannot be judged on the outcomes of a fixture that generates more sound, fury and, on occasion, nonsense than any other in British football.

Were Rangers to finish their first campaign back in the Premiership in second place any sane critic would consider that a job pretty well done. But if it were to come accompanied by three more alarmingly one-sided Old Firm games, and a colossal points-winning advantage for Celtic’s title, then sanity might exit pursued by a light blue bear.

A hammering at Parkhead is one thing, a drubbing on home soil another altogether.

“We understand the significance and the importance and the emotions involved in this game,” Warburton. “It’s Ibrox against Celtic and it’s dealing with that.”

Warburton’s side have improved over the first half of the season, especially in the last month or so with solid victories over Hearts and Aberdeen. But so have Rodgers’ men.

Warburton may plead poverty compared to the neighbours but Rangers have a grander budget than Aberdeen and Hearts and there is little on-field difference between those three. Rangers have won only three league games this season by a margin of two goals or more. Hearts have done it seven times, Aberdeen six and Celtic 10 times.

“They have improved for sure,” said Erik Sviatchenko, although the Dane also believes his side have themselves progressed since crushing Rangers 5-1 at Parkhead.

“So if you take that into account it might be that the gap is bigger. You always talk about gaps but you also know that one game can change the perception of it.”

It is a fair point for Warburton to see his project as a long-term one – his perceived ability to build something for tomorrow is the reason the Football Association fancy him for the Under-21 job.

Dembele scored a hat-trick in the two sides' first meeting this season (Getty)

Yet the on-field evidence is that Celtic are currently improving faster than Rangers – drawing twice with Manchester City (and right there is an even wider budgetary gap) is a significant step forward from last season. Select a Glasgow representative side and not only would the 1-11, in old school terms, come from Parkhead so would most of those in the bench.

Under Rodgers, the likes of Stuart Armstrong, James Forrest and Callum McGregor are playing better than to Ronny Delia’s instruction. Andy Halliday has become a key player under Warburton, but Barrie Mackay has yet to have a persistent impact at the higher level and too much still depends on the ageless Kenny Miller as Martyn Waghorn and the Joes, Garner and Dodoo, have also lacked consistency.

Celtic will be without Tom Rogic, another thriving under Rodgers. There are no shortage of choices to fill his boots. Warburton has greater worries with Lee Wallace and Clint Hill struggling to be fit. Take away half the home side’s defence and that gap looks wider still.