Yet to concede at home in Europe this season and holding a 2-1 lead after the first leg, København are strong favourites to reach the round of 16 at Ludogorets Razgrad's expense.
Ludogorets Razgrad must do what no team has managed against København at Parken Stadium in UEFA competition this season – score a goal – if they are to have any hope of qualifying for the UEFA Europa League round of 16.
• København have the upper hand in this last-32 tie after winning 2-1 in Sofia on 16 February.
• The first leg was the clubs' first meeting and Ludogorets's first encounter with Danish opponents.
• FCK's record in five games against Bulgarian sides is W4 D0 L1 (W2 at home).
• FCK have not conceded in six European home games this season – four wins followed by two 0-0 draws.
• Ludogorets made it through from the UEFA Champions League group stage despite not winning a game; since beating Viktoria Plzeň 2-0 at home in the play-offs, they have not prevailed in eight matches (D4 L4).
• København have not featured in the spring phase of a European competition since losing to Chelsea in the 2010/11 UEFA Champions League round of 16. They previously reached the last eight of the 1991/92 UEFA Cup, but have yet to win – or score a goal - in four springtime UEFA games (D1 L3).
• Ludogorets's only previous springtime European campaign came in 2013/14, when they eliminated Lazio in the UEFA Europa League round of 32 en route to a round of 16 loss to Valencia.
Links and trivia
• The journey from Razgrad to Copenhagen is just short of 1,700km.
• København's Nicolai Boilesen and Ludogorets' Jody Lukoki were team-mates at Ajax (2011–14).
• København defender Tom Høgli (33) and midfielder William Kvist (32) both celebrate birthdays the day after this game.
• While playing for PSV Eindhoven, FCK captain Mathias 'Zanka' Jørgensen featured in two 2-0 defeats by Ludogorets in the 2013/14 UEFA Europa League group stage.
• Recently named goalkeeper of the year in the Danish Superliga, receiving 'Det Gyldne Bur' (the golden cage) from football magazine Tipsbladet, FCK's Robin Olsen kept a clean sheet when Sweden beat a Bulgaria team featuring Ludogorets' Vladislav Stoyanov, Svetoslav Dyakov and Marcelinho 3-0 in a European Qualifier on 10 October 2016.
• FCK's Andrija Pavlović was a trainee at Rad in Serbia while Ludogorets goalkeeper Milan Borjan was in the first team (2011–13).
• Ludogorets and København are among eight domestic champions involved in the round of 32, along with: APOEL (CYP), Olympiacos (GRE), Hapoel Beer-Sheva (ISR), Legia Warszawa (POL), Astra Giurgiu (ROU) and Beşiktaş (TUR).
• Now in his second spell as København coach, Ståle Solbakken has led the club to six Danish titles. A midfielder, he was capped 58 times by Norway and ended his career at FCK after being diagnosed with a heart problem. He has coached in Norway, Germany and England, as well as in Denmark.
• A defender for Slavia Sofia and Yantra Gabrovo, Ludogorets's Georgi Dermendzhiev spent much of his career as an assistant coach with the likes of Litex Lovech, Botev Plovdiv and Sliven. On the staff since 2011, he took charge of Ludogorets in summer 2014 and has guided them to two league titles.
• København won their only previous UEFA penalty shoot-out:
W 3-2 H v Ferencváros (2003/04 UEFA Cup first round)
• Ludogorets won their only previous UEFA penalty shoot-out:
W 6-5 H v Steaua (2014/15 UEFA Champions League play-offs)