The draw for the next round of qualifying fixtures took place in Nyon on Monday morning, prior to the second round getting underway.
Scottish giants Celtic now know that victory against Rosenborg, whom they beat in the preliminary stage 12 months ago, will set up a tricky two-legged tie against AEK next month.
The games will take place on August 7/8 and August 15, with Celtic Park to host the first leg.
Champions League third-qualifying round draw in full:
Celtic or Rosenborg vs. AEK Athens
FC Salzburg vs. Shkendija or Sheriff
Red Star Belgrade or Suduva vs. Legia Warsaw or Spartak Trnava
Kukes or Qarabag vs. BATE Borisov or HJK Helsinki
Astana or Midtjylland vs. Dinamo Zagreb or Hapoel Be'er Sheva
CFR Cluj or Malmo vs. Ludogorets Razgrad or Vidi
Standard Liege vs. Ajax or Sturm Graz
Benfica vs. Fenerbahce
Slavia Prague vs. Dynamo Kiev
PAOK or Basel vs. Spartak Moscow