Here is a guide to the action.
What: The final round of the Champions League group stage.
Where: In 18 stadiums across Europe.
When: Kick-off for all matches is at 9:00 PM on Wednesday.
Clubs qualified for the round of 16: Arsenal and Bayern Munich. Arsenal can become the first club to win all eight matches in the group stage. Bayern have lost only one match - away to Arsenal in November.
Also likely to miss the round of 16: Real Madrid, Liverpool, Tottenham, Paris Saint-Germain, Newcastle and Chelsea. The clubs heading into the final round occupy places 3–8, which do not guarantee a place in the round of 16.
Already through to the round of 16: Barcelona, Sporting, Manchester City, Atlético Madrid, Atalanta, Inter, Juventus, Dortmund, Galatasaray and Qarabag are guaranteed to advance.
May miss the round of 16: Marseille, Bayer Leverkusen, Monaco, PSV, Athletic Bilbao and Olympiakos are living dangerously, but it's worse for reigning Serie A champion Napoli, who needs to take points at home against Chelsea.
Tough task: Viktor Claesson and Jordan Larsson's FC Copenhagen must take points, preferably win, away at Barcelona; otherwise Copenhagen's Champions League season is over.
Have a chance: Ajax, Club Brugge, Bodø/Glimt, Pafos and Union Saint-Gilloise must win to reach the round of 16.
Already eliminated: Kairat Almaty, Villarreal, Slavia Prague and Frankfurt.
The matches: Leverkusen - Villarreal, Paris Saint-Germain - Newcastle, Manchester City - Galatasaray, Liverpool - Qarabag, Dortmund - Inter, Frankfurt - Tottenham, Arsenal - Kairat, Ajax - Olympiakos, PSV Eindhoven - Bayern Munich, Napoli - Chelsea, Union Saint-Gilloise - Atalanta, Atlético Madrid - Bodø/Glimt, Barcelona - Copenhagen, Athletic Bilbao - Sporting, Monaco - Juventus, Benfica - Real Madrid, Pafos - Slavia Prague, Club Brugge - Marseille.
Draw: The round of 16 draw will be made at 12:00 on Friday. Matches will be played on 17–18 and 24–25 February. On 27 February, the draw for the knockout bracket up to the semi-finals (28–29 April and 5–6 May) will be made.
The final will be played in Budapest on May 30.
