Manchester United will be among the 12 top seeds when the Europa League draw is made on Friday.
Manager Jose Mourinho will manage in Europe's secondary club competition for the first time in 13 years, having won the UEFA Cup when he was in charge of Porto in 2003.
United will join Schalke, Zenit St. Petersburg, Shakhtar Donetsk, Athletic Bilbao, Olympiakos, Villarreal, Ajax, Inter Milan, Fiorentina, Anderlecht, Viktoria Plzen in pot 1, with the draw taking place at midday BST, 7 a.m. ET on Friday, Aug. 26.
The 48 teams are separated into four pots ranked in order of UEFA team coefficient, which is based on a club's performance in the Champions League and the Europa League over the past five years.
No team can play a club from their own association. Clubs from Russia (Zenit, Krasnodar) and Ukraine (Zorya Luhansk) cannot be drawn in the same group for political reasons.
Seeded Pot 1: Schalke, Zenit St Petersburg, Manchester United, Shakhtar Donetsk, Athletic Bilbao, Olympiakos, Villarreal, Ajax, Inter Milan, Fiorentina, Anderlecht, Viktoria Plzen
Pot 2: AZ Alkmaar, Braga, Salzburg, AS Roma, Fenerbahce, Sparta Prague, PAOK, Steaua Bucharest, Genk, APOEL, Standard Liege, St Etienne
Pot 3: Gent, Young Boys, Krasnodar, Rapid Vienna, Slovan Liberec, Celta Vigo, Maccabi Tel-Aviv, Feyenoord, Austria Vienna, Mainz, FC Zurich, Southampton
Pot 4: Panathinaikos, Sassuolo, FK Qarabag, FK Astana, Nice, Zorya Luhansk, Astra Giurgiu, Konyaspor, Osmanlispor, FK Qabala, Hapoel Beer-Sheva, Dundalk
GROUP STAGE MATCHDAYS
September 15
September 29
October 20
November 3
November 24
December 8
Round of 32 draw: Monday, Dec. 12.