The 2017–18 UEFA Champions League qualifying phase and play-off round began on 27 June and ended on 23 August 2017.
[1] A total of 57 teams competed in the qualifying phase and play-off round to decide 10 of the 32 places in the group stage of the 2017–18 UEFA Champions League.
The schedule of the qualifying phase and play-off round was as follows (all draws were held at the UEFA headquarters in Nyon, Switzerland).
The team that scored more goals on aggregate over the two legs advanced to the next round.
If no goals were scored during extra time, the tie was decided by penalty shoot-out.
[2] In the draws for each round, teams were seeded based on their UEFA club coefficients at the beginning of the season, with the teams divided into seeded and unseeded pots.
For these draws (or in any cases where the result of a tie in the previous round was not known at the time of the draw), the seeding was carried out under the assumption that the team with the higher coefficient of an undecided tie advanced to this round, which means if the team with the lower coefficient was to advance, it simply took the seeding of its defeated opponent.
Prior to the draws, UEFA may form "groups" in accordance with the principles set by the Club Competitions Committee, but they were purely for convenience of the draw and for ensuring that teams from the same association (or associations with political conflicts) were not drawn against each other, and did not resemble any real groupings in the sense of the competition.
The 10 winners of the play-off round (5 in Champions Route, 5 in League Route) advanced to the group stage to join the 22 teams which entered in the group stage.
[2] Below were the participating teams (with their 2017 UEFA club coefficients),[3][4] grouped by their starting rounds.
The New Saints Linfield Víkingur Gøta Hibernians FC Santa Coloma Alashkert La Fiorita Europa FCI Tallinn Trepça '89 The first legs were played on 27 and 28 June, and the second legs were played on 4 July 2017.
Since the draw for the second qualifying round took place before the results of the previous round were known, the seeding was carried out under the assumption that the team with the higher coefficient of an undecided tie would advance to this round, which meant if the team with the lower coefficient was to advance, it simply took the seeding of its defeated opponent.
Qarabağ Partizan Žalgiris F91 Dudelange Budućnost Podgorica Hibernians[†] Samtredia Copenhagen BATE Borisov Astana Rijeka Sheriff Tiraspol Hapoel Be'er Sheva Žilina The New Saints[†] Kukësi Honvéd Alashkert[†] Spartaks Jūrmala Celtic Legia Warsaw Maribor Malmö FF Rosenborg
The losing teams in both sections entered the 2017–18 UEFA Europa League play-off round.
Celtic[†] Copenhagen[†] BATE Borisov[†] Legia Warsaw[†] Maribor[†] Vardar[†] Astana[†] Rosenborg[†] Slavia Prague
Qarabağ[†] Partizan[†] Rijeka[†] Sheriff Tiraspol[†] Hapoel Be'er Sheva[†] Viitorul Constanța Dynamo Kyiv Ajax Viktoria Plzeň CSKA Moscow Club Brugge
The losing teams in both sections entered the 2017–18 UEFA Europa League group stage.
A total of 20 teams played in the play-off round: Olympiacos Celtic Copenhagen
Maribor Qarabağ Astana Rijeka Hapoel Be'er Sheva Slavia Prague Sevilla Napoli Liverpool CSKA Moscow Sporting CP