It is hard to recall a match at Pittodrie that United fans will have dreaded more than this one.
While a heavy defeat isn’t guaranteed, it is extremely likely.
The gap between the clubs is currently as great as at any time in living memory but, of course, the old place used to hold no such fears for the Tangerines.
As a veteran of many a trip up the A90, I have fond memories of Paul Sturrock, Ralph Milne and Eamonn Bannon going toe-to-toe with the greatest-ever Aberdeen side before landing a few knockout blows.
Heck, it wasn’t even that long ago (well, actually it seems like a lifetime) that a certain Gary Mackay-Steven inspired United to a thrilling 3-0 victory in August 2014.
Since then, under the wily guidance of former Tangerines captain and one-time Tannadice managerial interviewee Derek McInnes, Aberdeen have confidently claimed their place as Scotland’s second-top team while United have fallen far.
Billy Dodds, a hero for both clubs as a player, even suggested this week that losing the cup-tie may not be a bad thing for Csaba Laszlo’s men because they would then be able to focus solely on trying to get promoted.
One thing that may surprise some in the Red Army is that the Dons have, at times, been getting cheered on from down here in the City of Discovery.
There may be some rivalry left over from the days of the New Firm (a term I have never embraced) and the battle of wits involving those managerial giants Sir Alex Ferguson and Jim McLean.
However, I personally have wished them well in their bid to mount at least some kind of challenge to Celtic over recent years and I’m sure a few United fans would say the same.
All that goodwill will disappear when the whistle blows on Sunday, of course.
In their heart of hearts, the travelling supporters will be fearing the worst and you really can’t blame them the way their team has been performing.
The confident, even arrogant, brushing aside of runaway Championship leaders St Mirren by the Dons in the previous round was noted with some trepidation.
Indeed, United’s best hope may be that there doesn’t seem to be any hope.
It will almost come as a shock if they take the lead, for example, and the Dons players may be as stunned as everyone else if that happens.
Still, the likeliest outcome is a repeat of what happened that day back in 2014. No, not a United victory, but a goal for a smiling and victorious.
My prediction is Aberdeen 3 Dundee United 0.