Real Madrid are among the teams facing the possibility of an early Champions League exit in Wednesday's final round of group games.
Thirteen-time European champions Real - who have never been knocked out at the group stage - need a victory over Borussia Monchengladbach to progress for the 23rd year in a row.
Chelsea, Liverpool, Manchester City and holders Bayern Munich are among the 10 teams already through to the knockout stages.
Here is the state of play going into the final round of group matches on 9 December.
Who is through to the knockout stages?
Group winners: Bayern Munich, Chelsea, Liverpool, Manchester City, Borussia Dortmund, Juventus
Runners-up: Porto, Sevilla, Lazio and Barcelona
TBC: RB Leipzig
Who still has something to play for?
Group A: Atletico Madrid, Red Bull Salzburg
Group B: Borussia Monchengladbach, Shakhtar Donetsk, Real Madrid, Inter Milan
Group D: Atalanta, Ajax
Group H: Paris St-Germain
When is the last 16 draw and how does it work?
The draw for the last 16 will take place on Monday, 14 December at Uefa's headquarters in Nyon, Switzerland.
Teams finishing top of their group will be drawn against a team finishing second in a different group.
Clubs cannot face a side they met in the group stage and, at this stage of the competition, teams from the same country cannot be drawn against each other. That is allowed to happen from the quarter-finals, the draw for which takes place on 19 March, alongside the semi-finals.
Teams will then be able to plot their route to the final, which is on 29 May at the Ataturk Olympic Stadium in Istanbul.
The last-16 ties are two-legged and will take on 16/17 and 23/24 February, and 9/10 and 16/17 March.
What do sides need to do to qualify?
Group H - Paris St-Germain to seal top spot?
Wednesday, 9 December - Paris St-Germain v Istanbul Basaksehir (17:55 GMT)
The match between Paris St-Germain and Istanbul Basaksehir on Tuesday was abandoned after a match official was accused of using a racist term towards one of the away side's backroom staff.
It will recommence on Wednesday from the 14th minute, with a new set of match officials.
PSG are certain of at least second spot but will go through as group winners if they beat Istanbul Basaksehir.
Group B - Real on the brink?
Wednesday, 9 December - Inter Milan v Shakhtar Donetsk, Real Madrid v Borussia Monchengladbach (both 20:00 GMT)
Another group that is wide open is Group B with all four teams still able to qualify. Leaders Borussia Monchengladbach travel to Real Madrid. If either side wins they are guaranteed to go through. The Germans will also progress with a draw. A point would only be enough for Real if Inter beat Shakhtar because of their superior head-to-head record over the Italians but not the Ukrainians.
A win takes Shakhtar through, and they would also progress with a draw if Real do anything but win. Inter have to win to reach the last 16 and even that would not be enough if the other game ends in a draw.
What about the other groups?
Atletico Madrid will progress from Group A providing they avoid defeat against Red Bull Salzburg in Austria (9 December, 20:00 GMT).
They will be joined by Atalanta, if they do not lose against Ajax (9 December, 17:55 GMT).
Which sides cannot reach the knockout stages?
The following sides are definitely out of last-16 contention.
Group A: Lokomotiv Moscow
Group C: Olympiakos, Marseille
Group D: FC Midtjylland (will finish fourth)
Group H: Istanbul Basaksehir (will finish fourth)
What about the Europa League?
Arsenal, Leicester City, Tottenham and Rangers have booked their place in the Europa League last 32. Here are the qualifiers from each of the groups so far:
Group A: Roma
Group B: Arsenal
Group C: Slavia Prague, Bayer Leverkusen
Group D: Rangers, Benfica
Group E: Granada, PSV Eindhoven
Group G: Leicester City, Braga
Group H: Lille, AC Milan
Group I: Villarreal
Group J: Royal Antwerp, Tottenham
Group K: Dinamo Zagreb
Group L: Hoffenheim, Red Star Belgrade
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