United face Villarreal, Celtic and Aalborg in Group E of this season's Champions League.
The European champions were last paired with Celtic two years ago, both clubs winning one match apiece in the group stage. Sir Alex's team triumphed 3-2 at OT and lost 1-0 in Glasgow, a result which saw the Hoops join United in the last 16.
United met Villarreal for the first time in 2005/06. Neither game yielded a goal and the Reds ultimately bowed out of Europe, while the Spanish side went through as group leaders with Benfica in second.
Aalborg are the unknown quantity in Group E, having never faced United before. However, the Reds have played other sides from Denmark in recent times, including Brondby and FC Copenhagen in the group stages of 1998/99 and 2006/07 respectively.
Dates for your diary
17 Sept - Villarreal (H)
30 Sept - Aalborg (A)
21 Oct - Celtic (H)
5 Nov - Celtic (A)
25 Nov - Villarreal (A)
10 Dec - Aalborg (H)
Group A - Chelsea, Roma, Bordeaux, Cluj
Group B - Inter Milan, Werder Bremen, Panathinaikos, Anorthosis
Group C - Barcelona, Sporting Lisbon, Basel, Shakhtar
Group D - Liverpool, PSV, Marseille, Atletico Madrid
Group E - United, Villarreal, Celtic, Aalborg
Group F - Lyon, Bayern, Steaua Bucharest, Fiorentina
Group G - Arsenal, Porto, Fenerbahce, Dynamo Kyiv
Group H - Real Madrid, Juventus, Zenit St. Petersburg, Bate