The Ibrox club had been performing poorly, both in attack and defence, in the Third Division in the build-up to the fifth round match. Draws at home to part-time rivals Elgin City and Montrose last month had suggested all would not go well up at Tannadice.
Ally McCoist's team, too, had only around 400 fans to cheer them on in Tayside due to a controversial boycott of the fixture.
And the absences of club captain and top scorer Lee McCulloch and young playmaker Lewis Macleod due to injuries were also far from ideal.
Not even the most optimistic Rangers supporter had expected anything other than a demanding day against quality SPL opposition. But few could have foreseen what transpired on a truly dreadful afternoon for the Glasgow club.
The paucity of the Rangers performance against Dundee United was a shock.
The painful 3-0 defeat may now have serious repercussions for those responsible. From just after kick-off, when Emilson Cribari and Ross Perry combined to gift Johnny Russell the opening goal, the visitors were in disarray.
The second goal they conceded was even worse. United captain Jon Daly was allowed to stroll unchallenged into the six-yard box and head home Willo Flood's free-kick.
Admittedly, Rangers fared better in the second half. They controlled the match for long spells until Russell killed the tie off with his second strike against the run of play. But they still created absolutely nothing; United keeper Radoslaw Cierzniak had no save of any note to make during the entire 90 minutes.
The likes of Sebastien Faure, Kyle Hutton, Chris Hegarty, Andy Little, Barrie McKay, Perry and Kal Naismith can, perhaps, be excused for the disgraceful showing due to their youth.
But Ian Black, Cribari, Francisco Sandaza, Dean Shiels, David Templeton and Lee Wallace? They should hang their heads in shame for producing such a toothless display.
Every one of that sextet – three of whom are full internationals – has a wealth of top flight experience and should have really acquitted themselves better. Far, far better.
Despite plying their trade in the fourth tier, they are still handsomely remunerated professional footballers.
Indeed, Rangers still have the second highest annual wage bill, around £7million, in the country. None of them gave their employers value for money in an embarrassing loss at the weekend that leaves their club with only the Third Division title still to play for.
"Our SPL players should have done better," said McCoist as he looked back on his team's third cup defeat of what has been a difficult season.
"I will not be critical of individuals, but it was a disappointing day for one or two of the older boys who would have hoped to have done better."
If there is a repeat of the Tannadice display then questions will have to be asked if certain players have a long-term future at the Glasgow club. Is, for example, Cribari the sort of character who Rangers can build their team around as they bid to move up the leagues and return to the SPL and Europe?
The Brazilian centre-half, who has previously played in Serie A for Empoli, Udinese, Lazio and Napoli, has been decent and dependable during his time in Scotland.
However, he was cruelly exposed on more than one occasion against the United side new manager Jackie McNamara was taking charge of for the first time.
"The quality of our defending was really poor as was the quality of goal we lost," said McCoist.
And as for Black! The midfielder, who was, along with Naismith, sent off near the end of the game, has often failed to attain the high standards he set with Hearts last season.
He was up to his old antics again at the weekend – he appeared more interested in clattering opponents than winning the ball at times – and it was no surprise at all when he was red-carded for a second bookable offence.
McCoist is, despite the 12- month transfer embargo he is operating under, currently attempting to persuade players who are free agents in the summer to sign for Rangers.
The capitulation to a United team that plays at the level they ultimately aspire to reach may have alerted him to positions where he needs to strengthen.
He has consistently stated this season that, despite their huge lead in the league, a team hastily cobbled together in the summer is nowhere near where it needs to be. He was proved correct on Saturday.
Still, the game at the weekend will have been eye-opening for him. Players he had reasonably expected to form the backbone of his team failed to show up.
It could, of course, just be down to a collective off-day. It is also debatable if playing in the Third Division is adequate preparation for taking on SPL opponents.
But if there are any more abject performances like it in the weeks and months ahead, if standards are allowed to plummet again, then it will be no surprise if there are significant changes in personnel.