Several sides are on the cusp of qualification for the knockout stage ahead of this week's Champions League action.
Groups A to D are in action Wednesday while the remaining four groups play out match-day five Tuesday, and several teams are one win away from the next round.
In Group A, Manchester United will book its ticket for the knockout stage with a win over Bayer Leverkusen at the BayArena, while even a draw will be enough if Shakhtar Donetsk is beaten by Real Sociedad. Leverkusen, meanwhile, seals progress if it beats United and Shakhtar spills points versus Sociedad.
Elsewhere, Real Madrid can seal the top spot in Group B with at least a draw against Galatasaray, while even defeat will see it through if Copenhagen fail to beat Juventus.
French champion Paris Saint-Germain is on the verge of qualifying from Group C as a draw at home against Olympiakos will see it progress, while even a loss will be enough if Benfica fails to beat Anderlecht. That outcome will also see Olympiakos seal a place in the next round.
In Group E, a draw for Chelsea against Basel would see the Blues playing Champions League soccer after Christmas, while even a loss will be enough if Steaua Bucharest beats Schalke. Schalke will qualify if it beats Steaua and Basel loses to Chelsea.
Furthermore, Arsenal will progress from Group F if it defeats Olympique de Marseille and the game between Napoli and Borussia Dortmund ends in either a victory for the Serie A side or a draw. Napoli, meanwhile, will book its ticket for the knockout stage with a win or a draw against BVB.
Zenit St. Petersburg can become the second team from Group G to reach the next round if it beats group leader Atletico Madrid and victory eludes rival Porto against Austria Wien.
Finally in Group H, AC Milan will reach the knockout stage if it beats Celtic in Glasgow and Ajax is beaten by Barcelona.