The first leg between the Reds and the Tunisian side will be played away from home on 9 October.
According to the draw of the tournament, last year's runners-up Ahly were given a bye into the second preliminary round.
Meanwhile, Monastir, who are making their first-ever appearance in the prestigious continental tournament, booked their place in the second preliminary round after defeating Rwanda's APR 3-0 to go through with a 3-1 aggregate win.
The Cairo giants had a season to forget last term, finishing third in the Egyptian Premier League for their worst position in 30 years.
They also lost the chance of winning a record third straight Champions League title after losing 2-0 to Morocco's Wydad in the final, which was played in Casablanca last May.
Last year, US Monastir, who finished as runners-up in the Tunisian league last season, were eliminated in the African Confederation Cup playoffs after losing to Moroccan side Raja 6-5 on penalties.
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)
Short link: