As a result of finishing third in the league phase, the Gunners will either face the winners of the knockout phase play-off between the 13th and 14th seeds, or the 19th and 20th seeds; AC Milan, PSV Eindhoven, Feyenoord or Juventus.
As Brest, Sporting CP, Manchester City, Juventus, Club Brugge, Celtic, Feyenoord, and Monaco finished the league phase in 17th to 24th, they were at home for the first-legs.
In the new league phase format, the top eight teams have progressed straight through to the last 16 and avoided a two-legged knockout play-off tie in the process.
The top eight from the league phase of the competition will face the eight winners of the knockout play-off ties in the last 16.
Arsenal, Liverpool and Barcelona are among the teams watching the Champions League knockout phase playoff stage with interest.
