With 10 points widely accepted as the magic number that usually puts a team through to the knockout stage of Europe's elite club competition, seven of the eight group leaders can get within a point of that with wins in this third round of games.
The week's most eye-catching fixture, though, is Tuesday's Group H encounter at the San Siro as Milan and Barcelona meet for a third season in a row.
The Spaniards triumphed 4-2 on aggregate in last term's round of 16 and they also met in the group stage the year before, drawing 2-2 in Spain and Barca winning 3-2 in Italy.
Barcelona also overcame seven-times European champions Milan 1-0 on aggregate in the 2005/06 semi-finals on their way to their second of four continental titles.
The match provides the Italians with not just a chance of revenge but also the possibility of going above their rivals in the Group H standings where Gerardo Martino's team lead with a perfect six points from two matches with Milan second on four.
It will also offer an opportunity for referee Felix Brych to try to forget about a mistake in the Bundesliga at the weekend when he awarded Bayer Leverkusen striker Stefan Kiessling a goal when the ball had passed through a hole in the side-netting.
In Group B, Real Madrid are already four points clear of second-placed Juventus before hosting them on Wednesday and while Carlo Ancelotti's men warmed up with a 2-0 victory over Malaga in La Liga at the weekend, the Italians lost 4-2 at Fiorentina.
"We're facing a club that really want this title, because of their history and their hunt for a 10th European Cup. I think it will be a nice challenge for us to go and compete with them at the Santiago Bernabeu, as well as at home. It will tell us how well our development is going."
In one of two Anglo-German meetings, Arsenal host Dortmund and their sharpest weapon, Mesut Ozil, will be very familiar to the visitors.
The Germany international used to play for Dortmund's bitter rivals Schalke 04 and has been in fine form since his close-season move to north London, netting twice in Saturday's 4-1 victory over Norwich City.
"Ozil has taken Arsenal up a level," Dortmund coach Juergen Klopp told British newspaper The Sun. "His tactical ability for offensive football is perfect, and that's what Arsene (Wenger) wants."
Klopp will be serving the second game of his two-match touchline ban, which was imposed for an outburst during their 2-1 defeat by Napoli in their Group F opener last month.
Arsenal's Premier League rivals Chelsea travel to Ozil's old club Schalke on Tuesday, hoping to catch up with the Group E leaders who have six points to three for Jose Mourinho's second-placed team.
Mourinho is, like Klopp, no stranger to angry eruptions at officials having been dismissed from the touchline in his side's 4-1 victory over Cardiff City at the weekend.
In Group G, Zenit St Petersburg forward Hulk is preparing to head back to his old side Porto on Tuesday, while group leaders Atletico Madrid travel to Austria Vienna having dropped their first La Liga points at the weekend.
Premier League clubs Manchester United and Manchester City will be aiming to make amends for dropped points on Wednesday with David Moyes' side hosting Real Sociedad in Group A and Manuel Pellegrini's men travelling to CSKA Moscow in Group D.