Tuesday, 2:45 p.m. ET
Manchester United vs. Bayer Leverkusen
A tough game for United in a group filled with solid teams. Bayer Leverkusen have started the Bundesliga season well and are up in third place. The hosts are definitely the favorites, though it wouldn't be surprising to see their German opponents pick up at least a point at Old Trafford.
Real Sociedad vs. Shakhtar Donesk
This game should also be close, though Shakhtar head in as favourites. The Ukrainian champions lost a few of their best players in the summer, though replaced them with yet more talent from South America. Despite home advantage, Real Sociedad -- who beat Lyon in the Champions League playoffs to get to the group stages -- could struggle.
Galatasaray vs. Real Madrid
These sides last met in a rather eventful game in last season's knockout stages, when Galatasaray took a shock 3-2 win over Real Madrid, though were still eliminated on aggregate. They will be hoping for a similar upset here, though chances are very slim for the Turkish side.
F.C. Copenhagen vs. Juventus
This game is an even more exaggerated David vs. Goliath matchup, as Italian champions Juventus travel to Denmark to play Copenhagen. The hosts are a stronger team than their compatriots Nordsjælland -- who held Juve to a draw in the group stages last season -- though the Old Lady are still expected to comfortably win.
Benfica vs. Anderlecht
Belgian side Anderlecht haven't made the group stages since 2006-07 and aren't expected to pull up any trees on their return to the Champions League proper. Benfica should start their European campaign with all three points.
Olympiacos vs. Paris Saint-Germain
PSG haven't had as good a start to the season as they may have hoped, though Laurent Blanc's side are still unbeaten as of yet. They should record victory away in Athens against Olympiacos, who will struggle to progress into the knockout stages,
Bayern Munich vs. CSKA Moscow
CSKA Moscow shouldn't cause Pep Guardiola's Bayern too many problems, as the defending champions start their title defence at the Allianz Arena.
Viktoria Plzeň vs. Manchester City
Manchester City have been consistent underperformers in the Champions League of late, though they've had a kinder draw this season. They head to the Czech Republic to play Viktoria Plzeň on Tuesday, with Manuel Pellegrini's team expected to shake off their recent league blues to pick up three points.
Wednesday, 2:45 p.m. ET
Schalke 04 vs. Steaua Bucharest
Schalke have started their Bundesliga campaign unconvincingly, though three consecutive victories should provide them with the momentum required to see off Steaua Bucharest at home on Wednesday.
Chelsea vs. Basel
Basel have a reputation as giantkillers, notably responsible for Manchester United's exit at the group stages a couple of seasons ago. However, the Swiss side are certainly outsiders in their trip to Stamford Bridge on Wednesday, with Europa League holders Chelsea looking for a winning start.
Marseille vs. Arsenal
Arsenal have an unenviable trip to Marseille to start their group stage campaign, though their recent excellent form gives them reason for optimism prior to this clash at the Stade Vélodrome. Having been drawn in such a difficult group, every point counts.
Napoli vs. Borussia Dortmund
In arguably the game of the opening Champions League round, Napoli host last year's beaten finalists Borussia Dortmund at the Stadio San Paolo. Rafael Benítez's team have been hugely impressive in Serie A so far, though this is their first real test. Dortmund are flying in the Bundesliga, so it'll be interesting to see how the partenopei stand up.
Austria Wien vs. Porto
Austria Wien are probably the weakest team in the Champions League and will do well to get anything from this game. Unfortunately for them, they almost certainly won't.
Atlético Madrid vs. Zenit St. Petersburg
This is one of the most intriguing games of the round, between two of the Champions League's dark horses. Atléti may have lost Falcao this summer, though you wouldn't know it. They've won all four of their La Liga games so far, and sit joint-top of the table with Barcelona. Russian runners-up Zenit St. Petersburg will try to halt their charge.
AC Milan vs. Celtic
Celtic had a scare against Shakhter Karagandy in the Champions League playoffs, though eventually saw off the stubborn Kazakh side. Their reward is a trip to Milan, where they'll look to capitalise on Max Allegri's side's dodgy start to the Serie A season.
Barcelona vs. Ajax
Ajax and Barcelona are famous for devising and utilising (at least a variant of) total football, with both sides said to have played some of the best football ever seen. However, the Dutch champions have fallen on hard times continentally, and will find it difficult to come away from their Barça trip with any points -- not least with the Spanish champions having started so well under Gerardo Martino.