In the qualifying phase and play-off round, each tie was played over
two legs, with each team playing one leg at home. The team that scored more goals on aggregate over the two legs advanced to the next round. If the aggregate score was level, the
away goals rule was applied, i.e., the team that scored more goals away from home over the two legs advanced. If away goals were also equal, then thirty minutes of
extra time was played, divided into two fifteen-minutes halves. The away goals rule was again applied after extra time, i.e., if there were goals scored during extra time and the aggregate score was still level, the visiting team advanced by virtue of more away goals scored. If no goals were scored during extra time, the tie was decided by
penalty shoot-out. 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. A seeded team was drawn against an unseeded team, with the order of legs in each tie decided by draw. Due to the limited time between matches, the draws for the second and third qualifying rounds took place before the results of the previous round were known. 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 formed "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 were not drawn against each other, and did not resemble any real groupings in the sense of the competition. ==Teams==