Holders Real Madrid look to have been handed an easy passage to the last 16, but the likes of Paris Saint-Germain, Tottenham Hotspur and Manchester United may find things difficult over the coming weeks.
Read on as we look at the eight Champions League groups.
Atletico have emerged as one of Europe’s top clubs over the past few years, but Dortmund could prove troublesome.
The additions of Axel Witsel and Thomas Delaney has boosted the German side and they have looked more impressive than their La Liga counterparts this season. They could be worth an interest at 10/3 to win the group.
Monaco’s policy of selling their best players could hinder their chances in the Champions League, while the latest sports betting odds of 500/1 to win the tournament suggest Brugge will be out of their depth.
Champions League second favourites Barcelona are on a recovery mission, having been dumped out of the competition by Roma in the quarter-finals last term.
They have made an impressive start in La Liga and are worthy 4/9 favourites to top this group. Inter Milan and Spurs are likely to fight out second place and preference is for the Italian side.
Spurs’ failure to strengthen their squad this summer has already had an impact in the Premier League and they could even come under pressure from PSV in this section.
Punters will be backing Liverpool and Paris Saint-Germain to progress from Group C, but Carlo Ancelotti will fancy his chances of toppling one of them with Napoli.
The Reds have spent heavily this summer and should finish in the top two, leaving PSG and Napoli to fight out the other spot.
The French club are desperate to win the competition, but Napoli may surprise them. Crvena Zvezda are expected to finish bottom.
On paper this is the weakest group and it wouldn’t be a surprise to see any of the teams qualify for the knockout stage.
Porto (5/4) and Schalke (2/1) are the favourites to progress, but Lokomotiv could be the team to upset the odds.
They won the Russian title for the first time in 14 years last season and have since added Fedor Smolov, Benedikt Howedes and Eder to their squad.
Bayern should breeze through this group, but who will finish second is less clear.
Ajax have made some significant signings this summer, bringing in Dusan Tadic and Daley Blind after finishing second in the Eredivisie last season.
However, both Benfica and AEK are capable of qualifying alongside Bayern and it would be a brave move to predict who will win the battle. Slight preference is for Benfica.
An injury to Kevin De Bruyne hasn’t had a major impact on City and they should easily finish top of this group.
The other three teams look closely matched, but Shakhtar could reward punters by edging the race for second.
The Ukrainian club has held on to highly-rated manager Paulo Fonseca and they are fancied to finish ahead of Lyon and Hoffenheim.
Real Madrid are chasing a fourth Champions League title in a row and they should win Group G at odds of 1/6 despite being without Cristiano Ronaldo.
Roma reached the semi-finals last season and they appear strong enough to take second place.
Neither CSKA or Viktoria Plzen look to possess the quality to trouble the big two in this group.
All eyes will be on ex-United star Ronaldo as he takes on his former club for the first time in a Juventus shirt.
Both clubs should qualify for the next stage, although Valencia are capable of upsetting the odds if their numerous new signings gel.
Young Boys ended Basel’s domination in Switzerland, but the Champions League is a huge step up in quality and it’s difficult to imagine them springing any surprises.
MORE: The latest football news
MORE: The latest tennis news
BIOGRAPHY: Daniel Sturridge
BIOGRAPHY: Kepa Arrizabalaga