At least one former winner must drop out of the preliminary rounds for the Champions League after Benfica and PSV Eindhoven were drawn against one another in Monday’s playoff draw.
The match-ups for the ultimate 12-team qualifying round were drawn before the teams had played the preceding third qualifying round, meaning about one among the ties had four potential teams.
Salzburg and Brondby, the 2 teams to hitch the competition at this stage, were drawn together.
The composition of the other five pairings will be settled in two-leg ties which begin on Tuesday and Wednesday.
Benfica, who have emerged in seven finals in the competition winning two, must overcome Spartak Moscow to progress while 1988 winners PSV face Midtjylland of Denmark.
Three former finalists were also within the draw.
If Monaco manages to eliminate Sparta Prague they need to then beat Genk or Shakhtar Donetsk to return to the group stage.
Malmo, who faced former Cup Winners Cup winners Rangers within the third round, would then face Bulgarians Ludogorets or Greeks Olympiacos.
If Red Star Belgrade beat Sheriff of Moldova they might confront old Croatian rivals Dinamo Zagreb or Legia Warsaw.
The six winners will reach the group stage while losers will sink to the Europa League.
Champions League play-off draw, first legs Aug 17-18 August, second legs Aug 24-25:
Salzburg (AUT) v Brondby (DEN), CFR Cluj (ROM) or Young Boys (SUI) v Ferencvaros (HUN) or Slavia Prague (CZE), Malmo (SWE) or Rangers (SCO) v Olympiakos (GRE) or Ludogorets (BUL), Red Star Belgrade (SRB) or Sheriff Tiraspol (MDA) v Dinamo Zagreb (CRO) or Legia Warsaw (POL), Monaco or Sparta Prague (CZE) v Genk (BEL) or Shakhtar Donetsk (UKR), Spartak Moscow (RUS) or Benfica (POR) v PSV Eindhoven (NED) or FC Midtjylland (DEN)