The Basel midfielder is set to complete a £5 million move this week, and has completed a medical.
The Egyptian has also submitted a work permit application, of which the Gunners are hopeful will be approved this week.
The FA Cup clash with Sam Allardyce's Sunderland would be an ideal game in which to give Elneny his first action in an Arsenal shirt, even as a substitute.
Arsenal will be favoured heavily to win the game, while Premier League strugglers Sunderland are likely to rotate their squad, with top flight survival their priority over a cup run.
Elneny will be Arsenal's first signing of the window, but it is unclear whether manager Arsene Wenger has plans to secure any more deals, with the Frenchman notoriously secretive over his transfer plans.