Arsene Wenger has confirmed that Arsenal have completed the signing of holding midfielder Mohamed Elneny from Basel for an undisclosed fee.
The Egypt international had long been linked with a move to the Emirates, but work permit complications initially held up the deal.
However, Elneny has now become Wenger's first signing of the January transfer window.
"Elneny will of course join us," Wenger said after Arsenal's 3-3 draw against Liverpool at Anfield on Wednesday.
"He has joined us. We will see if he can qualify for [the Premier League trip to Stoke City on] Sunday."
The 23-year-old came through the ranks of the Al Ahly youth academy, but joined El Mokawloon at the tender age of 16, before making the move to Basel in January 2013. He has since become an important first-team member at the Swiss champions, earning a transfer to Arsenal with his fine performances for the St. Jakob-Park club.
Arsenal were in the market for reinforcements due to their ongoing injury problems in midfield.
Jack Wilshere missed the entire first half of the 2015-16 campaign due to physical problems, while Francis Coquelin and Santi Cazorla are still recovering from injury.