The top-tier UEFA Champions League is heading into the last week of the group stage as only four tickets are available to enter the round of 16.
Twelve clubs including defending champions Manchester City have secured their last 16 place each before the sixth matchday that will begin on Tuesday.
Bayern Munich (Group A), Arsenal and PSV Eindhoven (Group B), Real Madrid (Group C), Real Sociedad and Inter Milan (Group D), Atletico Madrid and Lazio (Group E), Borussia Dortmund (Group F), Manchester City and RB Leipzig (Group G), and Barcelona (Group H) have qualified for the knockout stage.
Copenhagen, Galatasaray and Manchester United in Group A, Napoli and Braga in Group C, Paris Saint-Germain, Newcastle United and AC Milan in Group F, and Porto and Shakhtar Donetsk in Group H are bidding for one of the four posts in last 16.
In Group A, one of the tough groups in the 2023-24 campaign, Galatasaray will visit Copenhagen in a thriller at Parken Stadium on Tuesday, where the Turkish team had good memories at least two decades ago.
Galatasaray won the 2000 UEFA Cup at Parken after beating Arsenal on penalties, and the Istanbul powerhouse's current head coach Okan Buruk was a starter in the final.
For the runners-up position there is a relentless race among the three Group A clubs – Copenhagen, Galatasaray and Manchester United.
Bayern Munich have 13 points to win the group.
Copenhagen and Galatasaray have five points each, and fourth-place Manchester United are on four points in five matches. Only one of these clubs will be in the Champions League's next round.
In their Group A opener in September, Galatasaray rescued one point after a 2-2 home draw with Copenhagen in Istanbul. French defender Sacha Boey and Brazilian winger Tete scored two late goals in a Champions League thriller against 10-man Copenhagen.
Galatasaray on Tuesday must win in Denmark to be in the last 16. Manchester United will face Bayern Munich in a home match at Old Trafford on the same day.
Manchester United must beat already qualified Bayern Munich and hope a draw between Copenhagen and Galatasaray to progress.
But if there were a winner in the Copenhagen vs. Galatasaray fixture, Manchester United need three points against Bayern Munich to finish third, which means the English club will go to the second-tier UEFA Europa League knockouts.
Bayern Munich, who took a goalless draw with Copenhagen in the previous fixture in Munich, are unbeaten in 39 Champions League group games, which is a record.
Bayern have won 35 group stage games in the top-flight tournament since a 3-0 loss at Paris Saint-Germain in September 2017.
Both Group A fixtures will begin at 2000GMT.
Next week will see the Champions League round of 16 draw.
Champions League Matchday 6
Tuesday's fixtures are as follows:
Lens - Sevilla
PSV - Arsenal
Manchester United - Bayern Munich
Copenhagen - Galatasaray
Napoli - Braga
Union Berlin - Real Madrid
Inter - Real Sociedad
Salzburg - Benfica
Wednesday
Leipzig - Young Boys
Crvena zvezda - Manchester City
Atletico Madrid - Lazio
Celtic - Feyenoord
Borussia Dortmund - Paris Saint-Germain
Newcastle United - AC Milan
Porto - Shakhtar Donetsk
Antwerp - Barcelona
