Manchester City travel to Russia to face CSKA Moscow in their third match of Champions League Group E on Tuesday.
Here, we look at the key battles that could decide a match both sides will be anxious to win.
Chelsea manager Jose Mourinho has spoken of his simmering discontent over uncommunicative national team managers over the treatment of his players in the continued absence of striker Diego Costa.
Ramires and Andre Schurrle trained with Chelsea on the eve of the Champions League Group G clash with Maribor, but Diego Costa was absent.
Brazil midfielder Ramires (groin) and World Cup-winning Germany forward Schurrle (illness) missed Saturday's win at Crystal Palace.
Costa, scorer of nine goals in seven Premier League games for the leaders, was also missing at Selhurst Park after persistent hamstring problems this season.
Costa was again absent for the first 15 minutes of Monday's training session, which was open to the media, with an otherwise full squad at Jose Mourinho's disposal.
CSKA Moscow striker Ahmed Musa claims Manchester City are "weak" opponents but it is unfair that his team have to face them without supporters.
Gareth Bale has been ruled out of Real Madrid's Champions League trip to Liverpool this week through injury - reports say.
Join Adrian Chiles and co. at Stamford Bridge for live coverage of Chelsea's clash with Slovenian champions Maribor.
Ten years ago today, Lionel Messi made his debut for Barcelona. It's fair to say he's done okay in the last decade, not least in the Champions League, as this highlight reel shows…