Berlin - DPA
Several of Europe's big hitters will be hoping to join Barcelona in the last 16 of the Champions League, while others will be hoping to avoid missing out.
European champions Real Madrid, Manchester City, Bayern Munich, Roma, Juventus, Inter Milan and Porto all need a point in the penultimate group-stage matches to go through.
Others will be hoping to seal their places with victories, while teams like Paris Saint-Germain, Tottenham Hotspur and Valencia are battling for survival.
Group C is one of the tightest groups where Napoli will be through if they beat Red Star Belgrade and PSG fail to beat Liverpool.
Juergen Klopp's Liverpool side are also aiming to seal progress with a victory in Paris if Napoli avoid defeat, but PSG, who could see the return from injury of strikers Neymar and Kylian Mbappe, will be fighting for their lives.
"We're aware this game with Liverpool is crucial for us," coach Thomas Tuchel said on the club's website.
"We're going to have to find the right balance between the aggression required to win while also keeping our cool. We'll have to have a certain faith in our ability, stay focused and keep our aim in mind."
Bundesliga champions Bayern Munich are also under pressure after recent poor form has increased speculation over the future of coach Niko Kovac.
Bayern will be looking to the Champions League to provide the antidote to their present malaise, knowing a draw at home to Benfica in Group E on Tuesday will be enough to progress.
After a 3-3 draw at home to lowly Fortuna Dusseldorf on Saturday, club president Uli Hoeness said the team were "playing really bad football, uninspired football, and most of all football without confidence."
Kovac, he said, would be in charge on Tuesday but "we will use the next days to find out what's going on" - comments interpreted as but a short reprieve for the Croatian coach.
Ajax will also be through with a win at AEK Athens, or if Benfica fail to get a point in Munich. The Portuguese side must win to have a chance of a top-two finish.
Premier League champions Manchester City control their own fate and need to avoid defeat at second-placed Lyon to go through from Group F on Tuesday. The French side are also looking to advance with a win, and a draw might also be enough.
Hoffenheim meanwhile take on Shakhtar Donetsk in the group needing a win to stay in contention.
Roma and Real Madrid come together in Group G knowing a draw will put both through at the expense of CSKA Moscow, who greet Viktoria Plzen.
Real coach Santiago Solari has Keylor Navas back fit but the Costa Rica keeper has not been named in the squad and Thibaut Courtois is likely to stay in goal.
Serie A champions Juventus need a draw at home to Valencia in Group H, where Manchester United are at home to Young Boys and could also advance with a victory if Valencia do not win in Turin.
"If we play with the same philosophy against Young Boys then we won't win," United manager Jose Mourinho said after a goalless draw with Crystal Palace in the league.
Both Bundesliga leaders Dortmund, at home to Club Brugge, and Atletico Madrid, hosting Monaco, know victories in Group A on Wednesday will be enough to reach the knock-out phase. Brugge must win to keep their hopes alive.
Barcelona are already assured of progress from Group B ahead of the visit to PSV Eindhoven on Wednesday, while Tottenham meet Inter Milan in a crunch match. Spurs must win at Wembley while Inter need a draw.
Portuguese champions Porto are out to clinch top spot in Group D on Wednesday when they take on Schalke, who know a win will also be enough - and both sides could afford a defeat if Galatasaray fail to win at Lokomotiv Moscow.