German international, Shkodran Mustafi is set to join Italian club AS Roma on a loan deal.
Roma has an option to sign the player permanently for €25million (£22.9m/$27.7m).
The 27-year-old is yet to play a single game for the Gunners this season.
He was left out of their successive victories against Newcastle and Burnley in the Premier League.
Meanwhile, the Gunners had earlier signed former PSG defender, David Luiz from Chelsea on deadline day.