[1] Villarreal were the defending champions, having defeated PSV 4–2 in the previous season's final, but were eliminated in the group stage.

Twelve teams in Premier League 2 were invited to represent England in the tournament, while European teams that qualify for the knockout stages were guaranteed an invite for the following season's competition.

The group winners, and two best runners-up, progressed into the knockout phase of the tournament.

[2] All matches - including fixtures between non-English teams - were played in England and Wales.

Valencia, Feyenoord, Sparta Prague, Dinamo Zagreb, VfL Wolfsburg, and Hertha Berlin were the new international entrants in the 2016–17 season.