Each tie in the knockout phase, apart from the final, is played over two legs, with each team playing one leg at home. The team that has the higher aggregate score over the two legs progresses to the next round. In the event that aggregate scores finish level, the away goals rule is applied, i.e. the team that scored more goals away from home over the two legs progresses. If away goals are also equal, then thirty minutes of extra time are played, divided into two fifteen-minutes halves. The away goals rule is again applied after extra time, i.e. if there are goals scored during extra time and the aggregate score is still level, the visiting team qualifies by virtue of more away goals scored. If no goals are scored during extra time, the tie is decided by penalty shootout. In the final, the tie is played as a single match. If scores are level at the end of normal time in the final, extra time is played, followed by penalties if scores remain tied.
In the draw for the round of 32, the twelve group winners and the four better third-placed teams from the Champions League group stage (based on their match record in the group stage) are seeded, and the twelve group runners-up and the other four third-placed teams from the Champions League group stage are unseeded. A seeded team is drawn against an unseeded team, with the seeded team hosting the second leg. Teams from the same group or the same association cannot be drawn against each other. In the draws for the round of 16 onwards, there are no seedings, and teams from the same group or the same association may be drawn against each other.