Everything you need to know ahead of the Premier League match at Old Trafford on Sunday afternoon
Wenger and Mourinho have had fierce battles on the touchline over the years, with the latter previously labelling the Arsenal manager a "specialist in failure", while Wenger once said: "When you give success to stupid people, it sometimes makes them more stupid."
The Gunners top four hopes are out of sight and with the Europa League hanging by a thread, it's expected that Wenger will ring the changes for Sunday's historically intense clash.
Former Arsenal forward Alexis Sanchez will also feature against his old club for the first time since leaving the north Londoners in January.
Arsenal injuries
Henrikh Mkhitaryan is running again in training but won't be fit for Sunday's game, with Wenger targeting the match in Madrid as a potential return date for the Armenian.
Egypt midfielder Mohamed Elneny is out with ankle ligament damage and is expected to be on the sidelines for at least a fortnight.
Spanish midfielder Santi Cazorla remains a long-term absentee with an Achilles injury, although he was pictured training on the Emirates pitch before the Europa League semi-final against Atletico on Thursday.
Arsenal potential starting line-up
Wenger could rest a number of players ahead of Thursday's crucial Europa League semi-final second leg against Atletico Madrid.
The likes of Alex Iwobi and Sead Kolasinac could start, while Ainsley Maitland-Niles, Calum Chambers or Rob Holding are able to fill in for Laurent Koscielny, with the Frenchman carefully managing his chronic Achilles problem.
Pierre-Emerick Aubameyang is expected to return up front and could play alongside Welbeck, with Petr Cech expected to return between the sticks.
Man Utd injuries
Other than the continued absence of Sergio Romero with a knee injury, United should be heading into Sunday's game with a clean bill of health. Antonio Valencia did leave the field early at Wembley due to a muscle problem, but he is expected to be available to start against Arsenal.
Man Utd Potential Starting Line-Up
Mourinho may well decide to go with an unchanged side as he looks to get Champions League qualification secured at the earliest opportunity, especially given how well his side played in the victory over Tottenham.
However, there will be the likes of Marcus Rashford, Anthony Martial, Marouane Fellaini, Luke Shaw, Eric Bailly, Marcos Rojo and Victor Lindelof all hoping to be considered for call-ups after missing last week's win at Wembley.
With trips to Brighton and West Ham to come, followed by a final league fixture at home to Watford, the United boss will need to decide how he can make the most of his squad while keeping the momentum up before the Reds head back to the national stadium in three weeks' time.