Defeat to one set of Mapgies is unfortunate. Losing to a second set of black and whites next Sunday would not only be careless, but would remove from Steve Bruce the excuse to which he stuck after this significant setback, namely that he was keeping his powder dry for more important matters ahead.
Saving themselves for the visit of Newcastle in the Tyne-Wear derby, the Wearside club failed to pay heed to the threat posed by Notts County, who made light of the 52-place gulf between the clubs. Their's was a richly merited victory.
Despite making numerous changes, Bruce could still send out a side that featured £50m of talent and was packed with internationals, but little good it did him as the Premier League team were undone by the manager's former Manchester United team-mate, Paul Ince.
Unsurprisingly, Bruce cut a dejected figure in the aftermath of a defeat which was very much on the cards once the identity of the team entrusted by the 50-year-old to ensure progress to the next stage became apparent. Ince, who has suffered only one defeat in 11 games since taking charge at Meadow Lane in October, saw his side take their place in round four after an absorbing 90 minutes.
"There's no worse feeling than this," Bruce conceded. "One thing's for certain, there won't be a repeat of this display against Newcastle, we can't afford a repeat and we won't let it happen." For the Sunderland manager's sake, let's hope he is right.
Bruce added: "I won't make excuses because that wouldn't be fair on Notts County. We didn't take part until I changed things round in the second half but the fact remains that we had international footballers out there who've been knocking on my door asking for a chance and they were found wanting."
The League One team were ahead as early as the fifth minute thanks, in part, to the non-intervention of Stuart Attwell, a referee with history when it comes to incurring the wrath of the Sunderland manager, having allowed a controversial goal for Liverpool when Sunderland had to settled for a point at Anfield in September.
Craig Westcarr's hopeful flick from a Ben Davies centre from the left should have made for a routine claim for Simon Mignolet, in goal for the hosts, but the young Belgian appeared to be impeded by a combination of the veteran County forward Lee Hughes and Sunderland's Kieran Richardson, causing him to drop the ball into his net. Those in red and white on the pitch and in the stands clearly expected a well-positioned Attwell to award a foul against their goalkeeper, but no such call came.
It was a lead the visitors were not to relinquish, thanks to some quite heroic defending and some woeful finishing from Sunderland's £25m forward pairing of Darren Bent and Asamoah Gyan, who continue to struggle together, a fact which must be of growing concern to Bruce. Both expensively acquired forwards were guilty of at least three glaring misses as the hosts sought a way back, although Bent atoned somewhat with an 81st-minute penalty, his 11th goal of the season, after Ricky Ravenhill had brought down the recalled midfielder Andy Reid in the area, as the hosts piled on the pressure.
The forward's confident spot kick, sending Stuart Nelson the wrong way, only halved the deficit, Hughes having doubled the visitors' lead six minutes earlier, following up to slot home his 10th goal of the season and sixth in seven games from an acute angle after Mignolet had saved his first attempt with his legs.
"It's a fantastic win," Alex Rae, Notts County's assistant manger, said. The Scot has been assigned post-match press duties by the superstitious Ince during the club's impressive seven-game unbeaten run, and the former Sunderland midfielder added: "We seemed to find an extra yard all over the pitch. You can say that Steve Bruce made plenty of changes but they still had a side packed with internationals so it's a victory to savour.
"It's a win for our fans because they live for days like this and rightly so."
Referee: Stuart Attwell
Man of the match: Hughes
Match rating: 7/10