What you might not already know about the play-offs

Napoli v Nice
The clubs met in pre-season friendlies in 2015 and 2016, with Nice winning 3-2 at home and Napoli prevailing 3-0 at the Stadio San Paolo 12 months later. Nice's star man Mario Balotelli misses the game through injury along with summer signing Wesley Sneijder

İstanbul Başakşehir v Sevilla
Istanbul Başakşehir's Emmanuel Adebayor and Gaël Clichy played in a 3-0 win for Arsenal against Sevilla in the 2007/08 UEFA Champions League group stage.

Hapoel Beer-Sheva v Maribor
Maribor midfielder Marwan Kabha is the third Israeli to play for Maribor after predecessors Sintayehu Sallalich and Dudu Biton.

Celtic and Astana met last season©Getty Images

Celtic v Astana
Celtic prevailed when these sides met in last season's third qualifying round. A 1-1 draw in Kazakhstan was followed by a 2-1 success for the Scottish club in Glasgow; Leigh Griffiths scored in both games, with Moussa Dembélé's 90th-minute penalty in the second leg proving decisive. Yuri Logvinenko registered Astana's first-leg goal.

Olympiacos v Rijeka
This is Rijeka's fifth consecutive season in Europe, with their most successful campaigns in that run coming in 2013/14 and 2014/15, when they contested the UEFA Europa League group stage. Olympiacos are aiming to reach the group stage for an 18th time.

Kick-offs 20:45CET unless stated