Thierry Henry will go straight into Arsenal's squad after signing on loan from New York Red Bulls, with captain Robin van Persie set to be rested.
Ivory Coast forward Gervinho is absent at the start of international duty ahead of the African Nations Cup, but Morocco striker Marouane Chamakh is available before his delayed departure.
Defender Johan Djourou is suspended after his red card at Fulham, while Kieran Gibbs (groin), Thomas Vermaelen (calf), Bacary Sagna (ankle), Carl Jenkinson (back), Andre Santos (ankle), Abou Diaby (hamstring) and Jack Wilshere (ankle) are all out.
Leeds were rocked ahead of the trip with news Paddy Kisnorbo will miss the rest of the season with a knee injury.
The defender suffered the problem in the 2-1 win over Burnley and scans have shown ligament damage which will require surgery and sideline him for at least six months.
Fellow defender Alex Bruce is struggling with a hamstring tear and will be assessed ahead of the journey to the capital.
However, United's defensive worries could be eased after Tom Lees (concussion) and Darren O'Dea (hip) returned to training following recent injuries.
Winger Robert Snodgrass remains sidelined following his appendix operation last Thursday, as does skipper Jonny Howson, who has missed the last five games due to a knee injury.
On-loan winger Andros Townsend has been given permission to play by parent-club Tottenham, with boss Simon Grayson confirming he is targeting new signings ahead of the clash.
Arsenal (squad): Almunia, Miquel, Mertesacker, Squillaci, Koscielny, Walcott, Rosicky, Song, Ramsey, Coquelin, Arteta, Henry, Benayoun, Szczesny, Arshavin, Chamakh, Oxlaide-Chamberlain, Park.