British clubs return to Europa League action on Thursday after last week's opening round of group matches.
Here, the PA news agency takes a closer look at the opposition clubs.
Dundalk: Filippo Giovagnoli was only appointed in August after the Lilywhites parted company with Vinny Perth, following their Champions League exit against NK Celje.
Royal Antwerp: A former Croatia international, Ivan Leko guided the club to the Belgian cup last season and previously won the league with Club Brugge.
AEK Athens: Massimo Carrera is coming up to his one-year anniversary at AEK having previously managed Xanthi and Spartak Moscow.
Lech Poznan: A former centre-back who won one cap for Poland, Dariusz Zuraw has been at the club since April 2019, winning 27 of his 60 matches in charge.
Lille: Christophe Galtier has been with the club for three years since replacing Marcelo Bielsa and has won 55 of his 112 games.
Dundalk: They made their European debut in the 1963–64 European Cup and their best performance came in 1979-80 when they reached the last 16.
Royal Antwerp: Antwerp were runners up in the Cup Winners' Cup in 1993 when they lost to Parma. They have only qualified for Europe twice since 1995.
AEK Athens: They were the first Greek team to compete in the group stage of the Champions League in 1994–95, reached the quarter-finals of the European Cup (1968–69) and UEFA Cup semi-finals in 1977.
Lech Poznan: The Polish side have pedigree in Europe having played in the Cup Winners' Cup and European Cup and regularly reach the Europa League but this is their first group stage for four years.
Lille: Lille qualified for Europe for the first time in the club's history in 2001-02, reaching the Champions League. They also finished bottom of Group H last season, twice losing to Chelsea.
Dundalk: Third in the League of Ireland, they lost their opening Europa League game to Molde last week and were beaten 1-0 by Waterford at the weekend.
Antwerp: They have won their last five games in all competitions and top the Belgium First Division by a point.
AEK Athens: One win in the last four, which came in a 1-0 victory at Ioannina on Sunday.
Lech Poznan: They sit 11th in the Polish Ekstraklasa after two wins from seven and were beaten by Benfica last week.
Lille: Second in Ligue 1 and level on points with Paris St Germain, they are unbeaten in the league this term.