The Dutchman may have tried to make too many changes too quickly to the London side's playing style as they have lost first three Premier League games of the season.
Frank de Boer has the vibe of being the wrong man, in the wrong place, at the wrong time at struggling Crystal Palace
The milestone could be reached on September 20.
It will be Frank de Boer’s 86th day in charge of Crystal Palace. Or, to put it another way, one more than the 85 he mustered at the helm of Inter Milan.
Normally an 86-day anniversary would not be worth marking, let alone celebrating. Yet these are not normal times, even for a club that, including interim regimes, has had 15 managerial reigns since 2010 alone.
Pointless and goalless, they go to Burnley on Sunday, with the question if De Boer will soon be jobless.
The chairman Steve Parish scarcely sounded the definition of a supportive employer when he said last week: “It's not been great, it's a results-based business, so if you don't get wins... Frank knows that.”
This, it is suggested, could be his last game. This, De Boer said on Friday, is not “a one-day project” but it might be a day to end an experiment.
Conclusions are being reached rapidly. One is that he is the wrong man in the wrong place at the wrong time. This feels a mess of Palace’s making which De Boer has compounded by being too didactic.
The Dutchman rejected the chance to manage Liverpool in 2012 and has had plenty of time to repent subsequently.
An ambition to work in England was belatedly realised this summer but Palace felt the poisoned chalice he grasped because of an absence of healthier alternatives.
De Boer was appointed with a remit to be revolutionary and to transform Palace’s style of play, but without the budget to recruit his sort of players.
Before Palace spent £26 million (Dh126m) to bring back Mamadou Sakho on deadline day, the only purchase was the Ajax defender Jairo Riedewald, whose display in the 3-0 defeat to Huddersfield Town suggested he is ill-suited to English football.
A manager who spoke of bringing the Ajax blueprint to Palace has tried to change too much, too fast with too few alterations on the playing staff.
A side accustomed to a counter-attacking gameplan and having a minority of possession are suddenly supposed to excel on the ball.
Rather than the finest Dutch sides, De Boer has brought back unwanted memories of Louis van Gaal, where ineffectual sideways passing was followed by direct football.
Meanwhile, a group used to playing 4-3-3 have been reconfigured in a 3-4-3 shape.
De Boer reverted to Allardyce’s tactics for the second half of the loss to Swansea, to his players’ evident pleasure.
“When we changed the formation we played much better,” said an undiplomatic Luka Milivojevic. It added to the impression that De Boer has not managed to persuade his charges of the merits of his ideas.
Perhaps the Serbian midfielder was irritated by being used as a defender in pre-season. Similarly, winger Andros Townsend spent the warm-up games being used as a wing-back.
It created the impression square pegs were being crammed into round holes because of inflexibility. De Boer has insisted he is not didactic. Palace are likely to revert to 4-3-3 on Sunday.
It feels obvious to suggest that radical change is difficult to effect successfully; it seems as though he and Palace are only belatedly realising that.
Selhurst Park had seemed an anachronism, and not just because of its antiquated feel, as the last holdout of the British manager, an endangered species in an increasingly cosmopolitan league. The suspicion, though, is that Palace will soon revisit their past.
Sam Allardyce is reportedly uninterested in a return to Palace, though the Croydon-born Roy Hodgson could be an available candidate.
But the very fact that names are being mentioned shows how precarious De Boer’s position is. Already. Again.