Wednesday's Champions League action includes high-quality matches such as Tottenham versus Inter and Paris Saint-Germain against Liverpool, as clubs seek a place in the next round.
PSG's Gianluigi Buffon could become the third goalkeeper to record a 50th clean sheet in the competition, with the Ligue 1 giants hosting last season's beaten finalists in a crunch clash in the French capital.
Monaco boss Thierry Henry will seek his first Champions League win as a head coach at the Wanda Metropolitano, while an injury-hit Barcelona are in action at PSV.
Here, we take a look at the key Opta numbers behind each of the eight matches on Wednesday in Europe's top competition.
Atletico Madrid v Monaco
18 - Monaco have not kept a clean sheet in their last 18 Champions League games, the longest run of this kind by any French club in the competition.
16 - In contrast, Atletico have only lost one of their last 16 home games in the Champions League, winning three in a row. That defeat came last September, 2-1 against Chelsea.
Borussia Dortmund v Club Brugge
5 - Of the eight goals Dortmund have scored in the Champions League this season, five have come from substitutes. Left-back Raphael Guerreiro is the only Dortmund player with more than one Champions League goal in 2018-19.
12 - Club Brugge have played 12 matches away to German opposition in the Champions League and they have not won any of them, losing on both of their previous visits to Dortmund.
PSV v Barcelona
8 - In the reverse fixture, Lionel Messi scored his eighth hat-trick in the Champions League. Barca won the game 4-0.
12 - PSV are without a win in 12 games in the Champions League, a longer run without victory in the competition than any other Dutch team.
Tottenham v Inter
5 - All five of the previous meetings between Spurs and Inter have been won by the home side. Inter have triumphed three times, including the reverse fixture earlier in the group stage.
17 - Son Heung-min has made 17 appearances in the Champions League, more than any other Tottenham player, but he has not scored in his past four games in the competition.
Napoli v Red Star Belgrade
20 - In the reverse fixture, Napoli recorded 20 shots but could not break Red Star down, the game ending in a goalless draw. It was the most shots Napoli have ever had without scoring in the Champions League.
25 - Red Star's 25 attempted shots in the Champions League this season is the lowest total of any team in this year's competition after four rounds of fixtures.
PSG v Liverpool
20 - PSG have not lost any of their last 20 home games in the Champions League. The last team to win at Parc des Princes in the competition was CSKA Moscow back in December 2004.
48 - Liverpool have scored 48 goals in the Champions League since the start of last season, more than any other club. Mohamed Salah (12), Roberto Firmino (12) and Sadio Mane (11) have contributed 73 per cent of those goals.
Lokomotiv Moscow v Galatasaray
5 - Lokomotiv Moscow are on a run of five straight losses in the Champions League. The Russian outfit have never before been beaten six times in a row in the competition.
3 - Galatasaray have scored three goals in the Champions League this season and they have all come from set-pieces. One was from a corner, one was a penalty and the other came from a direct free-kick.
Porto v Schalke
4 - Schalke's four goals in the Champions League have been scored by four players with four different nationalities: German Mark Uth, Austrian Guido Burgstaller, American Weston McKennie and Swiss Breel Embolo.
6 - In their last seven home games in the Champions League, Porto have won six times. The home side has also never lost in the five previous meetings between Porto and Schalke.