West Ham have been drawn in the same group as Anderlecht in the Europa Conference League, while Hearts will meet Italian side Fiorentina.
The Hammers are the top seeds in Group B and as well as facing Belgian side Anderlecht, formerly managed by Vincent Kompany, they will also meet Romania's FCSB - better known as Steaua Bucharest - and Danish outfit Silkeborg IF.
David Moyes' side reached the semi-finals of the Europa League last season, losing out to eventual winners Eintracht Frankfurt, but had to settle for a place in the Conference League this term after finishing seventh in the Premier League.
Scottish Premiership side Hearts, meanwhile, have been handed a tough draw in Group A, after dropping into the Conference League following their failure to qualify for the Europa League this week.
In addition to top seeds Fiorentina, Robbie Neilson's Jam Tarts face Turkish side Istanbul Basaksehir, for whom Mesut Ozil plays, with FK RFS of Latvia as the outsiders of the pool.
Irish side Shamrock Rovers have two trips to Scandinavia to look forward to in Group F after being drawn with Norwegian outfit Molde, Swedish side Djurgardens and top seeds Gent, of Belgium.
