Both sides won in the EFL Cup in midweek in contrasting fashion, Arsenal cruising past Nottingham Forest 5-0 at the Emirates Stadium on Tuesday before United laboured to a win on penalties after Rochdale held them to a 1-1 draw at Old Trafford the following night.
A litany of legendary names have met in this fixture over the years, from Roy Keane and Patrick Vieira's bruising midfield battles to Wayne Rooney and Thierry Henry's spectacular goals and tormenting of defences.
Unai Emery and Ole Gunnar Solskjaer might well wish they could borrow from one another's squads over the course of the week, with rapid-fire fixtures in the Europa League and Premier League following this match.
Here, Sports Mole has selected its strongest combined XI from the two squads, using only players available on Monday.
Despite their unconvincing form, United come into this game having conceded just six goals to Arsenal's 10, so Spain's David de Gea earns the nod over Germany's Bernd Leno in a meeting of two high-quality goalkeepers.
At the back, Arsenal's much-maligned defence can only contribute new £25m full-back Kieran Tierney, who is likely to make his Premier League debut at United following his move from Celtic.
The balance is different further up the pitch, where Dani Ceballos has been a creative revelation for entertaining Arsenal during the early stages of his loan spell from Real Madrid.
Nicolas Pepe's price tag is perhaps weighing heavily on him during his first months at the club - the Ivory Coast winger became Arsenal's record signing and the third-most expensive Premier League buy of all time when he joined for £73m in the summer.
The 24-year-old will be hoping his penalty in the nervy 3-2 win at home to Aston Villa will be the first of many for his new club.
Fellow winger Daniel James has looked a steal by comparison, scoring three times in his first six matches following a move for around £15m from Swansea City.
The 21-year-old has looked entirely unfazed by Premier League and European defences, firing in a spectacular early opener in the 1-1 draw at Southampton.
The athletic, mercurial Paul Pogba is charged with patrolling behind our three attacking midfield choices, fresh from returning for a forgettable comeback against Rochdale in midweek.
Greenwood's imagined strike partner, Pierre-Emerick Aubameyang, is one of the first names on this combined teamsheet, looking a strong contender to finish at the top of the Premier League scoring charts during a scintillating start to the season.