Manchester United will travel to Turkish giants Fenerbahce, now coached by Jose Mourinho, among their eight games in the league phase of the new-look Europa League, the draw for which took place in Monaco on Friday.
The Old Trafford club won the Europa League with Mourinho as coach in 2017. He recently became coach of Fenerbahce, who were knocked out of the Champions League in the third qualifying round.
United will also notably play at home to 2022 Europa League runners-up Rangers and go to Portugal to play Porto, another of Mourinho's old sides.
Tottenham Hotspur, the other English representative in the competition, will also take on Rangers, in their case away from home.
In addition, Ange Postecoglou's side will play at home to Roma and go to Istanbul to face Turkish champions Galatasaray.
The format of the Europa League has changed for this season, along the same lines of the new-look Champions League.
The number of clubs in the competition proper is now 36, all of whom are placed into one league but split into four pots of seeds.
Each participant plays eight games, facing two clubs from each pot, one at home and one away.
For Rangers, other opponents will include Lyon at home, Olympiakos away, and Nice away in France.
Other clubs involved in the competition include former European champions in Ajax as well as FCSB of Romania, who won the 1986 European Cup as Steaua Bucharest.
Eintracht Frankfurt, who beat Rangers in the final two years ago, are present along with Athletic Bilbao, whose stadium will host this season's final.
The top eight at the end of the league phase -- which runs until the end of January -- will advance to the last 16, while the teams finishing from ninth to 24th will advance to a play-off round to decide the remaining last-16 spots.
The bottom 12 in the league phase will be eliminated, with no clubs dropping down into the Conference League ahead of the knockouts, and no teams parachuting down from the Champions League as in the past.
UEFA have said that dates for all fixtures will be announced on Saturday. The first group games will be played on September 25 and 26, a week after the opening matchday of the Champions League.
This season's Europa League final will be played in Bilbao on May 21 next year. Atalanta won the trophy last season, beating Bayer Leverkusen in the final in Dublin.
