What to expect in the Champions League this week
The Uefa Champions League is in its 64th season and the 27th since it was renamed from the European Champion Clubs' Cup.
The final will be played at the Wanda Metropolitano in Madrid, Spain. Real Madrid are the defending champions, having won the title for three successive seasons in 2015/16, 2016/17 and 2017/18.
A total of 15 national associations are represented in the group stage. 1899 Hoffenheim, Red Star Belgrade (1991 European champions) and Young Boys will make their debut appearances in the group stage (although Red Star Belgrade have appeared in the European Cup group stage).