Although only a handful of teams will harbour serious hopes of winning the Champions League, many will feel they have a strong chance of progressing past the group stages and into the last 16 of the competition.
The vast majority of the big guns remained quiet on the final day of the transfer window, but some of the less fancied teams in each of the eight groups did make some last-minute acquisitions to their squads.
Roma sealed perhaps the biggest capture by beating Juventus to the signature of AC Milan striker Marco Borriello.
The 28-year-old ran the risk of being frozen out at the San Siro following the arrivals of Zlatan Ibrahimovic and Robinho and moves to their Italian rivals on an initial season-long loan with the chance to make the deal permanent for £10.7m.
Roma are in Group E of the Champions League with last year’s beaten finalists Bayern Munich, Basel and CFR Cluj and are 15/8 to finish at the head of the standings and reach the second round.
Lyon are the 7/4 favourites to top Group B and chose to strengthen their defence by bringing in Pape Diakhate on loan from Dinamo Kiev.
The Senegal international was also heavily linked with Arsenal, but joins Yoann Gourcuff among the new arrivals at the French giants.
Arsenal are 2/5 to top Group H, but both Braga and Shakhtar Donetsk will fancy their chances of causing a mini upset and progressing as winners.
The Portuguese outfit have sealed a deal for Custodio Castro and are 6/1 to finish at the head of the group, while Shakhtar, 9/2 to top the group, have signed young Brazilian Bruno Renan from Villarreal and Armenian midfielder Henrik Mkhitaryan from Metallurg Donetsk.
An Italian team are 7/1 to win the Champions League, with Roma available at 28/1. See the whole Champions League winners market.