The Basel midfielder is poised to move to the Emirates Stadium in a £7m deal and become Arsene Wenger's first January signing.
However, the deal could be delayed due to issues over a work permit following the FA's crackdown on signing players from outside the EU earlier this year.
Egypt currently lie 57th in FIFA's world rankings which means Elneny doesn't automatically qualify for a work permit as the FA's criteria is limited to the top 50 countries.
Under the old rules, Elneny would have qualified for a work permit as they extended to the top 70 countries in the world rankings.
It means the Gunners are likely to have to appeal for the 23-year-old to be granted a permit.
However, there are unlikely to be any major issues due to Elneny featuring in every competitive international for Egypt over the past two years, meaning the deal could still be confirmed next week.
Elneny will provide immediate cover for injured midfield trio Santi Cazorla, Francis Coquelin and Jack Wilshere.
Arsenal are top of the table going into the new year and Wenger confirmed yesterday he planned to be active in the transfer market as he looks to secure a first title since 2004.
"I will be busy that is for sure," said Wenger.
"I am already busy and I said already one month ago we are a bit short to deal with all the competitions we face, especially in midfield. We will be busy, yes."
