Celtic, Rangers and Crystal Palace are among the British teams who have found out their play-off opponents in the Champions League, Europa League and Conference League.
Scottish Premiership champions Celtic will face Kairat Almaty or Slovan Bratislava in the Champions League play-off round.
The first leg is set to be in Glasgow on August 19/20, with the return match on August 26/27.
Should Celtic win, Brendan Rodgers’ side will again qualify for the league phase, while a defeat over two legs would see them drop into the Europa League at the league phase stage.
Should Rangers get past Viktoria Plzen in their third-round qualifier, they will face the winners of Salzburg and Club Brugge in the play-off round.
They play the home leg on Tuesday August 5 before visiting Plzen the following week on Tuesday August 12.
However, things are a bit more complicated for Premier League side Crystal Palace, who will face either Fredrikstand from Norway or Midtjylland from Denmark in their Conference League qualifiers.
Midtjylland beat Hibernian in the last round, thanks to a 119th-minute overhead kick winner at Easter Road.
However, Crystal Palace could still return to the Europa League with their appeal against their demotion to be heard before the Court of Arbitration for Sport set for Friday, with an outcome expected on Monday August 11.
If they are successful, they will return to the Europa League and go straight into the league phase.
But if they are not successful, they will face either Fredrikstand or Midtjylland, with the first leg expected to be played on Wednesday August 20 or Thursday August 21.
They will find out their exact opponents when the third round of qualifying is completed on Thursday August 14.
Nottingham Forest will potentially replace Crystal Palace in the Europa League or Conference League depending on the outcome of the Eagles’ appeal.
Elsewhere in the Europa League, Aberdeen will face FCSB of Romania or Drita of Kosovo in their play-off round.
The first leg is set to take place at Pittodrie on August 21, with the return match a week later.
Jimmy Thelin’s side are guaranteed a form of group-stage football this season after winning the Scottish Cup.
Should Hibernian get past Partizan Belgrade in the third round, they will take on AEK Larnaca of Cyprus or Legia Warszawa of Poland for a place in the Conference League.
The Easter Road club dropped into the competition after losing to FC Midtjylland in their Europa League qualifier.
Dundee United will be up against AIK of Sweden or Hungarian side Gyori ETO in the play-off round, if they get past SK Rapid next.
Jim Goodwin’s side qualified for the third-round qualifier after victory over FC UNA Strassen.
Northern Irish champions Linfield will play either HNK Rijeka from Croatia or Shelbourne of the Republic of Ireland in their play-off round. However, they must progress past Vikingur of Faroe Islands to set-up the tie.
Larne, who played in the league phase of the Conference League last season, will face either Ballkani of Kosovo or Shamrock Rovers from the Republic of Ireland in the play-off round.
However, they will have to beat Portuguese side Santa Clara in their third qualifying round.