Deep in football conversation a few years ago Arsène Wenger outlined a theory he had about how the way managers talk about football can get into a player’s subconscious. This was not everyday football manager‑speak. “The way you speak out is seeds in the brains of your players,” he said. “It is subconscious, it is interesting. I am very interested in the subconscious force of the memory of a team.”

In a nutshell the concept is about how strongly certain messages, or raking up of past experiences, can come out in the way a team plays.

Heading north, to Old Trafford for the final time as Arsenal manager on Sunday, Wenger will have to choose his words carefully. His storylines at this particular theatre are among the most vivid of his 22 years in English football. Wenger has scaled football emotions at the most extreme levels of the spectrum at Old Trafford.

His three Premier League title wins all owed something extra to the shuddering results and pivotal performances at Manchester United. In 2002 Arsenal even stretched so high as to clinch the title with a victory on their rivals’ patch, much to United’s annoyance (needless to say they were not presented with the trophy there and then). But Wenger has also suffered some of his sharpest humiliations on the sideline of that same patch of grass. It still beggars belief that Arsenal could lose a Premier League game by a margin as harrowing as 8-2.

The glass-half-empty section in Arsenal’s fanbase taking position in the away corner of Old Trafford is probably a little more concerned about that memory flickering in the current team’s subconscious than the good times. The timing of this fixture is about as welcome as Shkodran Mustafi falling into a heap at the worst possible moment in front of Antoine Griezmann.

Wenger cannot be grateful for a game at Old Trafford squidged between the two emotionally loaded legs of the Europa League semi-finals. One last shot at farewell silverware has to dominate his approach, and a quick scan through Arsenal’s squad suggests this could be a long afternoon in Manchester if Wenger does the right thing and rests as many of his first-choice players as possible for Thursday’s second leg in Madrid.

One can almost imagine him scanning his squad list and taking it from there. So, who have we got? Start by ticking off Petr Cech and Pierre-Emerick Aubameyang at both ends. Defence: Calum Chambers, Rob Holding and Sead Kolasinac. Midfield: Henrikh Mkhitaryan, Ainsley Maitland-Niles, Alex Iwobi … erm.

There are three more spots available and Wenger has to decide whether to play any of his Europa League picks or throw down the gauntlet to some of the youngsters who have been on the fringe of the first team this season. Reiss Nelson, Joe Willock and Eddie Nketiah have had some experience. Maybe there is a debut going for Konstantinos Mavropanos, the Greek defender signed in January.

José Mourinho and his most experienced heavyweights may be licking their lips like a cartoon Big Bad Wolf.

José Mourinho and his most experienced heavyweights may be licking their lips like a cartoon Big Bad Wolf

It was 20 years ago that Wenger first felt how an away game at Old Trafford could somehow seem bigger and deeper than an ordinary away game. Arsenal were not entirely at full strength at the time – the young Austrian Alex Manninger playing in place of David Seaman in goal and George Weah’s cousin Christopher Wreh filling in for Ian Wright – but still had enough of the ingredients that would show off the best of the new mix of power and panache that made Arsenal title contenders in Wenger’s first full season.

United were favourites. The decade’s dominant team, champions for the previous two seasons, top of the league. Arsenal had games in hand but this meeting in the spring of 1998 would make or break them. Marc Overmars tormented United, nutmegged Peter Schmeichel to score the match‑winner, and stood there in celebration like a startled March hare while everyone around him sensed the significance of the moment – none more so than Wenger himself and Sir Alex Ferguson down the touchline, who could both tell this race had taken a mighty turn.

Unsurprisingly most of Wenger’s Old Trafford highlights occurred during the early years. Sylvain Wiltord’s winner in 2002 completed a big test of character. Manchester United’s players naturally wanted to do anything and everything within the rules to stop Arsenal from waltzing in and prising the trophy directly from their hands. A year later came the infamous 0-0 draw, etched in the memory for Ruud van Nistelrooy smacking a late penalty against the woodwork and Martin Keown barging into the Dutchman at the final whistle.

The following season United put revved up energy into halting Arsenal’s 49-game unbeaten run before it hit the half-century. The intensity of this series of matches, two proud powerhouses slogging it out, was utterly absorbing.

Wenger has been devastated by trips to Old Trafford more recently. He will never reflect fondly on being sent off in 2009 after kicking a water bottle and forced to watch from within a crowd that has habitually sung despicable chants about him.

The worst, naturally, was the 8-2 calamity in 2011, where the change in the nature of the contest between Fergie’s United and Wenger’s Arsenal was exposed in the Scot beginning to feel sympathy for an old foe who could no longer stand up with him in the same ring. Although that is an obvious nadir, Arsenal were soundly beaten by a pretty shameful 6-1 at Old Trafford in 2001 as well.

As recently as February 2016 Arsenal experienced another painful low at Old Trafford when they were in a position to kick on for a title challenge after narrowing Leicester’s advantage to five points. But their performance against an under‑strength United was feeble. They lost and the challenge petered out.

Sunday’s meeting is not remotely pivotal. The result means little to Arsenal and not much more to United, even though they would be glad to get closer to cementing second place ahead of Liverpool. Wenger has his memories and has to hope that for once this one is nothing special, so he can move on as calmly as possible to Madrid on Thursday.