The draw for the UEFA Champions League's playoff round took place on Friday.
The winners would advance to the Champions League's group stage while the losers will play in the group stage of the Europa League.
The game-one hosts are listed first.
These series start on August 16 with the return contests to be played on August 24:
FC Copenhagen (Denmark) vs. APOEL FC (Cyprus)
Dinamo Zagreb (Croatia) vs. FC Red Bull Salzburg (Austria)
These series start on August 17 with the return contests to be played on August 23:
Ludugorets Razgrad (Bulgaria) vs. FC Viktoria Plzen (Czech Republic)
Celtic FC (Scotland) vs. Hapoel Be'er Sheva (Israel)
Dundalk FC (Republic of Ireland) vs. Legia Warsaw (Poland)
These series open on August 16 with the return matches to be played on August 24:
Steaua Bucharest (Romania) vs. Manchester City (England)
Ajax Amsterdam (Netherlands) vs. FC Rostov (Russia)
BSC Young Boys (Switzerland) vs. Borussia Monchengladbach (Germany)
These series open on August 17 with the return matches to be contests on August 23:
FC Porto (Portugal) vs. AS Roma (Italy)
Villarreal (Spain) vs. AS Monaco (France)