Inter Milan welcome Slavia Prague to the San Siro for a Group F showdown in the UEFA Champions League. The Czech outfit are featuring in the group stage for just the second time.
Lyon and Zenit St. Petersburg clash in Group G of the UEFA Champions League. Zenit won both games against the hosts when the two were paired together in the 2015/16 group stage.
Liverpool kick-start their Champions League defence with a trip to the Stadio San Paolo to face Napoli. The Italian side beat the champions 1-0 here in last season's group stage.
Frank Lampard takes charge of his first European fixture as Chelsea host Valencia in the UEFA Champions League. Valencia have never beaten the Blues in six previous attempts.
Borussia Dortmund host Barcelona in the UEFA Champions League. Barca hope to banish the memory of their last European away game, a 4-0 loss to Liverpool in last year's semi-finals.
Club Brugge entertain Galatasaray in the opening match of Group A in the UEFA Champions League. The Turkish side have lost their last five away games in the competition.
Last year's beaten finalists Tottenham get their 2019/20 UEFA Champions League campaign started with a trip to Greece to face Olympiacos.
Two of Europe's heavyweights clash at the Parc des Princes as PSG host Zinedine Zidane's Real Madrid side in the UEFA Champions League.
Pep Guardiola's Manchester City side travel to Ukraine to face Shakhtar Donetsk in the opening Group C match of the UEFA Champions League.
Atletico Madrid and Juventus begin their quest to the win the UEFA Champions League with a Group D clash at the Wanda Metropolitano. Madrid's 2018/19 campaign was ended by Juve.
Arsenal visit Germany to face Eintracht Frankfurt in Group F of the UEFA Europa League. The Gunners play their first European match since last season's 4-1 final defeat to Chelsea.
Celtic travel to France to face Rennes on matchday one of the UEFA Europa League. Neil Lennon's side have been eliminated at the round of 32 stage in the past two campaigns.
Manchester United begin their UEFA Europa League campaign with a tie against Astana at Old Trafford. United lifted the title when they last featured in the competition in 2016/17.
Rangers take on Feyenoord in the opening Group G match of the UEFA Europa League. Rangers are unbeaten in 13 European matches at Ibrox, winning nine including all four this season.
Wolves qualified for the group stage with six fine wins and now host Braga at Molineux in their first Group K UEFA Europa League clash. Braga are unbeaten in seven European games.
Leicester City welcome Tottenham to the King Power Stadium in the Premier League.