The Champions League group stage has reached its climax, with seven places in the round of 16 still up for grabs.
The crucial action comes in Group H as Manchester United, Paris Saint-Germain and RB Leipzig fight it out for the two places, while Borussia Monchengladbach, Inter Milan, Real Madrid and Shakhtar Donetsk are in a titanic battle in Group B.
With that in mind, we run you through all the action ahead of what promises to be another unpredictable, dramatic week of Champions League action. Who will seal their places in the knockout stages?
GROUP A: Bayern Munich, Atletico Madrid, FC Salzburg, Lokomotiv Moscow
Standings: Bayern (13 pts), Atletico Madrid (6 pts), FC Salzburg (4 pts), Lokomotiv Moscow (3 pts)
Bayern Munich are through as group winners but second place is up for grabs. If Atletico Madrid avoid defeat against FC Salzburg, they go through, but if Salzburg win in Austria then it's Jesse Marsch's team who will progress.
Reigning champions Bayern Munich are already through as group winners so coach Hansi Flick may opt to rotate his squad following their 3-3 draw with RB Leipzig at the weekend. English wunderkind Jamal Musiala scored alongside a brace from Thomas Muller against Leipzig leaving Bayern at the top of the Bundesliga. They have Javi Martinez, Alphonso Davies, Jerome Boateng, Lucas Hernandez and Joshua Kimmich all out injured but should have too much for Lokomotiv.
Lokomotiv may yet need a result in Munich to secure a spot in the Europa League and will take heart from their 3-1 win over Rubin Kazan at the weekend where Vladislav Ignatyev scored twice. They have Mikhail Lysov, Dmitri Barinov, Daniil Kulikov, Ze Luis and Feder Smolov all out injured.
Both Salzburg and Atletico have a shot at reaching the knockouts, with the Austrians needing to beat Diego Simeone's side to go through. Jesse Marsch's Salzburg suffered a shock 1-0 defeat to Flyeralarm Admira at the weekend but will hope for more of the same from their last Champions League match where they won 3-1 at Lokomotiv. Antoine Bernede misses out through injury while Noah Okafor is a doubt.
Atletico beat Real Valladolid 2-0 on Saturday with Thomas Lemar and Marcos Llorente scoring. They have conceded just two goals in 10 La Liga games so Salzburg will have it tough to get through the Atletico defence. Simeone's side will be without Yannick Carrasco, Jose Gimenez and Diego Costa but will be favourites to go through.
Standings: Borussia Monchengladbach (8 pts), Shakhtar Donetsk (7 pts), Real Madrid (7 pts), Inter (5 pts)
This is all to play for. All four teams can progress: Gladbach need to avoid defeat to go through, while Real Madrid need to beat the German side to qualify. Shakhtar need to beat Inter to keep fate in their hands, while Inter need to win and hope for anything other than a draw in the other game.
This group is beautifully poised with all four teams still hopeful of gate-crashing the knockout stages.
Internazionale will go through to the knockouts if they beat Shakhtar Donetsk and the Real-Borussia match does not end in a draw. They won 3-1 on Saturday against Bologna with Romelu Lukaku scoring and Achraf Hakimi grabbing a brace. Aleksandar Kolarov and Matias Vecino are unavailable.
Shakhtar will progress if they win in Milan and travel with plenty of confidence having won 5-1 over Mynai at the weekend with Fernando, Manor Solomon and Mykola Matviyenko all scoring alongside a pair of own goals. Shakhtar drew 0-0 with Inter first time out, and will be without Ismaily, Viktor Kornienko, Yevgen Konoplyanaka and Junior Moraes. Inter should have too much for the visitors here.
Real Madrid's topsy-turvy season continued with a 1-0 win at Sevilla win at the weekend, thanks to a Yassine Bounou own-goal, but the pressure's on Zinedine Zidane's side to get a result against the impressive Borussia Monchengladbach. Sergio Ramos could play while Dani Carvajal has trainedm but Eden Hazard, Martin Odegaard and Federico Valverde will all miss out.
Gladbach drew 2-2 at Freiburg on Saturday with Breel Embolo and Alassane Plea scoring. They lost to Inter Milan in the last round, but know they may need a draw to go through. Jonas Hofmann and Ramy Bensebaini will both miss out for Marco Rose's side but there is a slim chance Nico Elvedi returns. We think Zidane will pull this one out of the hat and Madrid will progress.
GROUP C: FC Porto, Manchester City, Olympiakos, Marseille
Standings: Man City (13 pts), FC Porto (10 pts), Olympiakos (3 pts), Marseille (3 pts)
Man City and FC Porto are already through while Olympiakos and Marseille are competing for the Europa League spot.
Pep Guardiola's side are through as group winners so expect some rotation against Andre Villas-Boas' team. City saw off Fulham at the weekend 2-0 thanks to goals from Kevin De Bruyne and Raheem Sterling, leaving City sixth in the Premier League. They have Sergio Aguero still out injured but Guardiola's team should see off Marseille.
Marseille will be hoping to get a result in Manchester to book a spot in the Europa League and will travel over the Channel buoyed by their 2-0 win at Nimes on Friday. Dario Benedetto and Valere Germain both scored in their Ligue 1 victory and Villas-Boas only has winger Nemanja Radonjic absent.
Like Marseille, Olympiakos will be gunning for third and qualification to the Europa League and won 4-1 against Volos in Super League Greece on Saturday. Youssef El-Arabi grabbed a hat trick in that comfortable win, and they will fancy their chances against Porto on Wednesday. Veteran midfielder Mathieu Valbuena misses out through injury.
FC Porto drew with City last time out and edged past Tondela at the weekend in a 4-3 thriller. They had Mateus Uribe sent off late on, but moved third in the Primeira Liga thanks to Moussa Marega's double and other goals from Zaidu Sanusi and Mehdi Taremi. Ivan Marcano and Pepe both miss out. We think this will end in a draw with Olympiakos taking third spot.
GROUP D: Liverpool, Ajax, Atalanta, FC Midtjylland
Standings: Liverpool (12 pts), Ajax (8 pts), Atalanta (7 pts), FC Midtjylland (1 pts)
Liverpool are through as group winners while Ajax and Atalanta face each other for the second spot. If Atalanta avoid defeat in Amsterdam, they go through.
Danish champions FC Midtjylland will finish at the foot of Group D while Liverpool head into the knockouts as group winners so hopefully this'll lead to an expansive, end-to-end match. Midtjylland won 2-0 at Vejle BK on Saturday with Erik Sviatchenko and Alexander Scholz scoring. Liverpool breezed past Wolves 4-0 on Sunday with Jurgen Klopp juggling his squad with precision. Mohamed Salah, Georginio Wijnaldum and Joel Matip all scored, alongside a Nelson Semedo own goal, but expect Klopp to shuffle his pack again for Wednesday's trip to Denmark.
Virgil van Dijk and Joe Gomez remain long-term absentees while James Milner is also sidelined, but Trent Alexander-Arnold and Naby Keita returned in their win over Wolves. Liverpool should have too much for the hosts.
This will be one of the games of Matchday 6 with everything on the line as Atalanta travel to Ajax. If Atalanta avoid defeat, they'll go through to the knockout stages but a win for Ajax will see them leapfrog the Italians into second.
Ajax suffered a shock 2-1 defeat at home to Twente on Saturday with Dusan Tadic's second-half penalty not enough to earn a point, so they'll hope to fare better against Gian Piero Gasperini's side. Noussair Mazraoui, David Neres and Mohammed Kudus are all likely to be unavailable.
Atalanta's match at Udinese at the weekend was called off due to a waterlogged pitch so their previous match was the 1-1 draw at home to Midtjylland last week. Mattia Caldara and Robin Gosens will both miss out. We think this will end in a draw, with Atalanta going through.
Standings: Chelsea (13 pts), Sevilla (10 pts), Krasnodar (4 pts), Rennes (1 pt)
This group is already sorted: Chelsea go through as winners, Sevilla as runners-up and Krasnodar are in the Europa League.
Chelsea will top Group E and impressed at the weekend in their 3-1 win over Leeds with goals from Olivier Giroud, Kurt Zouma and Christian Pulisic. Giroud now has five in two, following his four-goal haul against Sevilla, and Hakim Ziyech is Chelsea's only injured player.
Krasnodar swiped aside Rotor 5-0 at the weekend thanks to braces from Ari and Viktor Claesson, and another goal from Magomed Suleymanov. They are already secure in third spot in this group. They will be without Dmitri Stotskiy and Sergey Petrov and will do well to get anything out of this trip to Stamford Bridge.
This group's standings are cemented with Rennes finishing fourth, and Sevilla going through as runners-up. Rennes' Champions League campaign has been disappointing and they fell to a 2-0 defeat at home to Lens at the weekend to leave them ninth in Ligue 1. Manager Julien Stephan said afterwards he was concerned by the team's "negative spiral" and said they have to behave like they are in a "fight against relegation." Rennes have a number of injury concerns with Daniele Rugani, Jonas Martin, Nayef Aguerd, Serhou Guirassy, Martin Terrier and Alfred Gomis all absent.
Sevilla lost 1-0 at home to Real Madrid at the weekend and have Marcos Aruna, Sergio Escudero, Munir and Tomas Vaclik all injured while Jesus Navas and Joan Jordan are rested. But they are already through in second and should get a result in France.
GROUP F: Zenit St. Petersburg, Borussia Dortmund, Lazio, Club Brugge
Standings: Dortmund (10 pts), Lazio (9 pts), Club Brugge (7 pts), Zenit (1 pt)
Borussia Dortmund are through but need a win to cement top spot. The winner of Lazio-Club Brugge will go through as runners-up with a draw enough for the Serie A side.
Anything other than defeat will see Lazio through and they'll hope to carry momentum into Tuesday's game from their 2-1 win over Spezia on Saturday. Ciro Immobile grabbed his 10th of the season alongside another from the incredibly talented Sergej Milinkovic-Savic. Senad Lulic and Vedat Muriqi are both unavailable for Tuesday's match but we expect Lazio to finish this group with a victory.
Club Brugge edged past Sint-Truiden 1-0 on Saturday thanks to David Okereke's second-half goal. They beat Zenit 3-0 last time out and have a fully fit squad for the trip to Rome.
Zenit hammered Ural Yekaterinburg 5-1 on Saturday in the Russian Premier League with Sardar Azmoun scoring a hat trick alongside goals from Artem Dzyuba and Douglas Santos. Dejan Lovren is out injured and will miss Tuesday's game.
Borussia Dortmund are struggling for goals without the injured Erling Haaland and needed a brilliant effort from Gio Reyna to grab a draw at Eintracht Frankfurt on Saturday. Borussia Dortmund are already through to the round of 16 and will want to finish top of the group but will have to do it without Manuel Akanji, Raphael Guerreiro, Thomas Delaney, Marcel Schmelzer and Haaland. We can see this ending all-square.
GROUP G: Juventus, Barcelona, Dynamo Kiev, Ferencvaros
Standings: Barcelona (15 pts), Juventus (12 pts), Dynamo Kiev (1 pt), Ferencvaros (1 pt)
Barcelona are in the driving seat and will keep top spot if they avoid defeat by three goals (or two goals, if the score is 3-1 or higher) against Juventus. Dynamo Kiev need to avoid defeat against Ferencvaros to get the Europa League spot.
This is a tantalising battle between two European giants for the top spot in Group G - and we're all hoping to see Lionel Messi up against Cristiano Ronaldo. But Barcelona head into this clash off the back of impressive European form, but a dismal performance in the league as they lost 2-1 to Cadiz on Saturday. Ronald Koeman has rotated Messi in their last two European games and he should start but Barcelona's injury list is ever-lengthening with Ousmane Dembele out with a hamstring injury. Gerard Pique, Ansu Fati and Sergi Roberto are all long-term absentees while Ronald Araujo should come back into the side.
Juventus need a victory to top Group G and edged past local rivals Torino at the weekend in Serie A, winning 2-1 thanks to goals from Weston McKennie and Leonardo Bonucci. They sit fourth in the Italian top flight and will be without veteran goalkeeper Gianluigi Buffon and defenders Merih Demiral and Giorgio Chiellini. Nothing will separate these sides on Tuesday evening.
This is a battle for the Europa League spot, which Dynamo Kiev will take if they avoid defeat. Dynamo beat Mariupol 2-1 at the weekend thanks to goals from Denys Harmash and Viktor Tsyhankov, while Ferencvaros won at Diosgyori 3-1. Dynamo will be without Oleksandr Tymchyk, Nazariy Rusyn, Mikkel Duelund, Mykyta Burda and Volodymyr Kostevych while Ferencvaros are at full-strength.
Standings: Man United (9 pts), PSG (9 pts), RB Leipzig (9 pts), Istanbul Basaksehir (3 pts)
PSG, Manchester United and RB Leipzig are all tied on nine points. A draw will see PSG through. Manchester United go out if they lose, but need a point at Leipzig to go through. Leipzig realistically need to beat United to go through.
This group is evenly poised with three teams all in with a shout of getting through to the knockout stages.
PSG know a win over Istanbul Basaksehir will see them book their spot in the round of 16 and they won 3-1 at Montpellier on Saturday thanks to goals from Colin Dagba, Moise Kean and Kylian Mbappe. Juan Bernat will miss out through injury, while Mauro Icardi, Julian Draxler and Pablo Sarabia are also doubts, but Thomas Tuchel will likely recall Neymar to the starting line-up.
Basaksehir lost 4-3 to Leipzig on Matchday 5, and drew 1-1 at Yani Malatyaspor on Saturday with Giuliano de Paula scoring. Martin Skrtel is suspended while Basaksehir will also be without Boli Bolingoli, Alexandru Epureanu, Mehmet Topal and Ifran Kahveci. PSG should win this comfortably.
Manchester United need to avoid defeat in Leipzig to go through, while Julian Nagelsmann's side will be looking for revenge having lost the return game 5-0 at Old Trafford.
Leipzig are playing some wonderful football at the moment and caused Bayern Munich all sorts of difficulty in their 3-3 draw on Saturday. Christopher Nkunku, Justin Kluivert and Emil Forsberg all scored against Bayern but Nagelsmann's side will be without Benjamin Henrichs, Hwang Hee-Chan, Lukas Klostermann and Konrad Laimer for Tuesday's match, while Dayot Upamecano is suspended.
Ole Gunnar Solskjaer's Manchester United came from behind to win 3-1 at West Ham on Saturday thanks to goals from Paul Pogba, Mason Greenwood and Marcus Rashford. They will be without suspended Fred, who saw red against PSG in their 3-1 defeat last week, while Luke Shaw, Anthony Martial, Edinson Cavani and Phil Jones are all absent. David de Gea remains doubtful with Dean Henderson on hand to deputise in goal. We think this will end in a win for Leipzig.