Going into the match the North London club lie in 10th, four places below sixth-placed United, with four points the difference between the two sides.
Here, Sports Mole looks at how the Gunners could line up for Saturday's match.
Arsenal go into this match without suspended leading goalscorer Pierre-Emerick Aubameyang following his dismissal against Crystal Palace, so 18-year-old forward Gabriel Martinelli will likely be brought in to replace him on the left.
The skipper is likely to be sorely missed, though, having netted 14 of Arsenal's 29 Premier League goals this season - only Danny Ings for Southampton has scored a higher proportion of his team's goals.
In midfield, Lucas Torreira will have a late fitness test after he was substituted at half time at Selhurst Park, which means Matteo Guendouzi will likely start in the centre of midfield.
The Bosnian will also face a late fitness, but will most likely start on the bench.