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Group stage

The 37 play-off winners are joined by holders Club Atlético de Madrid and the ten losing teams from the UEFA Champions League play-offs to make up the 48 clubs that go into the group-stage draw.
Group stage 
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Group stage

The 37 play-off winners are joined by holders Club Atlético de Madrid and the ten losing teams from the UEFA Champions League play-offs to make up the 48 clubs that go into the group-stage draw.

27 August at 13.00CET, Monaco

The 37 play-off winners are joined by holders Club Atlético de Madrid and the ten losing teams from the UEFA Champions League play-offs to make up the 48 clubs that go into the group-stage draw at the Grimaldi Forum.

The 48 sides are split into four seeding pots based on UEFA's coefficient system, with one from each drawn into the 12 groups. No team can meet another from the same association. Once the draw has been completed a computer draw will determine the final position of the sides within their group and therefore the order of the home and away matches.

http://www.uefa.com/uefaeuropaleague/draws/index.html#group+stage