August 28, 2011 was the nadir of Arsene Wenger's regime at Arsenal. There is no other way to view an 8-2 disembowelling by the team that were once his club's keenest rivals. An unreal scoreline dealt out a reality check. Three games into the season, and a faint flame of hope was already extinguished. Arsenal would not be competing for the Premier League title. Poor fortune played its part, but so did some extremely poor Arsenal play.
From those depths, it is to Wenger's credit as a manager that he eventually righted the ship, and returned the club to the Champions League at the end of the season. To do so, he had to rip up his modus operandi and begin again with an almost entirely new team.
That Sunday was also a day in which Samir Nasri played his first match for Manchester City, in a 5-1 win at Tottenham. By then, Cesc Fabregas was measuring for curtains in his new Barcelona abode and Jack Wilshere was in plaster. Robin Van Persie scored one of a pair of the most meagre of consolations, at a time when questions were beginning to be asked about his own contractual situation.
The week that followed saw Wenger panic buy in the transfer market for the first time in fifteen years at Arsenal. The dealings were hit and miss, though Mikel Arteta has become a mainstay, and Per Mertesacker his best defensive organiser.
Eventually, Arsenal muddled through, as Spurs faltered and Chelsea did too, and then became distracted by their quest for the Champions League. Arsenal finished third but when Jack Wilshere finally made his first-team return - in impressively fashion - against Queens Park Rangers last week, only Aaron Ramsey, Bacary Sagna and Thomas Vermaelen remained as starters from the team-mates he played his break-out season alongside.
Just over 14 months on from that last Old Trafford visit, Arsenal are not back at United's level. A pair of defeats to Norwich City and Schalke drew lineage from a home loss to Chelsea that dampened growing excitement about the new Arsenal. The QPR win was the first clean sheet in eight games, a statistic that muffled talk about Steve Bould tightening up the defence.
For United, that last Sunday of the summer was an afternoon when everything went right. It didn't get much better for them. The early weeks of 2011-12 saw an avalanche of United goals, but also a leaking defence that would eventually cost them on their title run-in.
Sir Alex Ferguson's answer to the problem of having eventually lost the Premier League title to Manchester City was from leftfield. It was to strengthen his attacking options rather than add muscle to his midfield or defence. Shinji Kagawa is injured for the moment, but it is Van Persie who will undoubtedly take the Saturday lunchtime focus, having first made clear he felt Arsenal could not match his ambitions, and then that he saw United as the type of club he saw himself signing for when he was a boy.
That sub-plot is sure to be the headline-maker on the morning of the game. Arsenal need to prove they can live without Van Persie, United want to show that taking Arsenal's prime mover from them has further lengthened the distance between the clubs.
Manchester United player to watch: Robin van Persie. He is the man who Arsenal fans will be watching like hawks. Any touch is due to be booed by those who have travelled north. Any appreciation of the outstanding final season he enjoyed at Arsenal will be drowned out by claims of avarice, even though Wenger admitted to the AGM last week that City offered him £300,000 per week. Arsenal's skipper and remaining hope is now United's greying goal machine. He has settled in tremendously, gallingly so for an Arsenal team that struggles for goals.
Arsenal player to watch: Bacary Sagna. The understandable warm glow resulting from the return of Jack Wilshere meant that the return of another long-term absentee was largely overlooked. There were others who felt that Carl Jenkinson, so improved since he suffered the deepest of any Gunner at Old Trafford in the 8-2, was unlucky to be displaced, but Sagna came back from a broken leg as if he had never been away - quietening Junior Hoilett and overlapping down the right. He and Jenkinson may even play in tandem on Saturday, with the Frenchman on the left if Wenger does not trust Andre Santos facing Antonio Valencia.
Key battle: Tom Cleverley v Jack Wilshere. The summer of 2011 featured much discussion of two young players who represented the future of England's midfield. There was a potential for them to be the new Frank Lampard and Steven Gerrard, since both favour similar territory on the pitch and might even end up at cross-purposes, but injuries have curbed such talk until now. Wilshere's 65 minutes at Emirates Stadium last week reconfirmed the stratospheric expectations Arsenal fans have of him. Cleverley's foot problem, sustained against Bolton the week after the 8-2 meant he would start just one more Premier League game for the rest of the season. Now he looks to be something of a first-choice, his development slower than last season, but on an upward curve, and the two, friends off the field, now look likely to cross footballing paths after such a long wait.
Trivia: Arsenal last won at Old Trafford in August 2006, through a late goal from Emmanuel Adebayor, after Tomas Kuszczak had earlier saved a penalty from Gilberto Silva. Jens Lehmann made a wonderful save to deny Ole Gunnar Solskjaer after that.
Stats: : Last season, Arsenal scored two goals at Old Trafford for the first time in 20 Premier League visits. No need to remind of the scoreline, though.
Odds: : Arsenal are 5.00 to win at : bet365:, with a draw on offer at 4.00. United are heavy favourites at 1.66. You cannot get odds on 8-2 at bet365.
Prediction: : United are yet to draw this season, so Arsenal to buck that trend by winning a point.