Spurs last played so few matches across a campaign in 2005-06, when they were not in Europe and crashed out at the first stage of both competitions to lower-league opposition, leaving Martin Jol's side with a 40-game season.
Unlike their League Cup third-round exit at Fulham way back in August, there is no need for recriminations or finger-pointing after this loss, only disappointment and frustration.
There is never any shame in losing to City, who ended their hoodoo at Spurs' new stadium, and Postecoglou's side matched the holders for the most part, restricting them to relatively few clear chances before Nathan Ake poked home in the 88th minute.
There was some doubt about the goal, with Spurs feeling Guglielmo Vicario was fouled at a corner, although it would have been soft to disallow it.
As Postecoglou ponders a run-in to May with just 17 League games to play, however, he will probably reflect on Spurs' own lack of threat in the final third.
This was their first blank under the Australian, and they finished the game with just one shot, a tame Brennan Johnson effort which was closed down by City goalkeeper Stefan Ortega in the second half.
In fact, they never really looked like scoring at all.
Postecoglou is optimistic that there is finally some distance between Spurs and the selection crisis which has depleted his squad for the best part of three months.
Micky van de Ven and Cristian Romero are fit again and were excellent against City; Timo Werner has arrived on loan; and James Maddison was back in action here, playing the final 18 minutes after more than two-and-a-half months on the sidelines.
But Spurs are still missing their most important player, Heung-min Son, who remains at the Asian Cup with South Korea. Son has scored in four of City's five defeats here, and found the net at both ends in the thrilling 3-3 draw at the Etihad last month.
The difference between then and now is Son, and his ability to stretch games in transition, create a chance from nothing and finish with either foot from almost anywhere around the box.
Everyone connected to Spurs should be (privately) willing South Korea to lose
Werner and Johnson did occasionally manage to get behind City or fashioned a glimpse of goal from the edge of the box. They were half-chances, not enough for the German or Johnson, but Son might have made one count - particularly given how much City fear him.
At No.9, Richarlison toiled but carried no threat in the final third and did not have a single shot nor even a glimpse of goal.
The return of Maddison will add much-needed creativity to Spurs and he will presumably start Wednesday's game at Brentford, while Dejan Kulusevski had an off day and can do better.
Spurs, though, still need someone to finish, and until Son returns their goal threat will remain worryingly thin on the ground.
South Korea face Saudi Arabia in the last-16 of the Asian Cup on Tuesday and it goes without saying that everyone connected to Spurs should be (privately) willing them to lose.