Teams of the same football association cannot meet.
The first and second place from the same group can't meet again.
The top members of the group can't meet.
Team two can't meet.
The second place in the group will play at home in the first leg.
Lottery procedure: put eight blue balls representing the second place of eight groups in a bowl, the first blue ball drawn represents the second place of a group, and play at home on the first match day of the knockout. According to the lottery rules, the computer will calculate which top teams this team can meet, and then draw out the opponents of this team with another bowl. There is a white ball in the bowl, which represents the top teams that this team may meet. If the computer shows that the second team can only meet one top team in the group, then the second team will automatically match the only top team that may be met without drawing lots. Subsequent draws will also be made in accordance with this procedure.