Former winners Real Madrid and Manchester United are two of the teams that could wrap up qualification to the Champions League knockout stages on Wednesday. Big-spending French champion Paris Saint-Germain, Olympiakos and Bayer Leverkusen can also qualify.

Group A

Bayer Leverkusen (GER) vs Man United (ENG): Both sides at the BayArena would secure qualification to the knockout stages with a victory. United knows a win will almost be enough to secure top spot, unless it loses at home to Shakhtar Donetsk in its final group game. A draw would suffice for both teams as long as Shakhtar loses at home to Real Sociedad in the group's other match. Leverkusen has been hit by the loss of Germany midfielder Sidney Sam while United also has several players on the treatment table, notably Michael Carrick. The Germans, however, have been in good form in the league and are up to second behind Bayern Munich following their 1-0 win at Hertha Berlin while United was stunned by an injury-time equalizer at Cardiff on Sunday. The pressure is on Leverkusen, as its final match is away to Sociedad while United knows it still has a home game at Old Trafford to come if it fails to secure qualification in Germany.

Shakhtar Dontesk (UKR) vs Real Sociedad (ESP): This is a must-win match for Sociedad if it harbors any hopes of prolonging its involvement in European soccer this season. While continuing its adventure in the Champions League will depend on it winning and Manchester United beating Leverkusen, and then Real beating the Germans in its final game with Shakhtar not stunning United at Old Trafford, a consolation spot in the Europa League is not so far-fetched. But it would still depend on beating the Ukrainians, as anything else would see it finishing bottom of the group. With Shakhtar's final match being away to United, it too will be feeling a win is necessary to keep its hopes of progressing alive, which could make for an open and entertaining match in Donetsk.

Group B

Juventus (ITA) vs FC Copenhagen (DEN): Antonio Conte's Serie A team comes into this match under pressure for its Champions League future. Bottom of the group and the only team yet to win a match, it must win this one to keep control of its own destiny. But even so, with a clash away to Galatasaray in its final group game, it knows it cannot afford to lose either of its last two fixtures - the alternative being certain elimination. Only two wins will guarantee it a last-16 spot, although with both its opponents also having to play Real Madrid, Juve will feel quietly confident a win and a draw will likely prove sufficient.

Real Madrid (ESP) vs Galatasaray (TUR): A point would be enough to send Real into the knockout stages and would also tie up top spot, barring an unlikely five-goal defeat at FC Copenhagen on the final matchday and assuming the Danes also win away to Juventus on Wednesday. Madrid will probably be without star forward Cristiano Ronaldo, who picked up a hamstring problem in a 5-0 win at Almeria on Saturday. The loss of a player who has scored 14 goals in his past seven matches for club and country would seem a blow, but such has been Real's domination of the group so far, and given it crushed Galatasaray 5-0 in Istanbul earlier in the campaign, it will be confident of doing enough to secure its passage through.

Group C

Paris Saint-Germain (FRA) vs Olympiakos (GRE): Paris Saint-Germain will qualify for the last-16 knockout phase with a draw at home to the Greek champion at the Parc des Princes, while Olympiakos will also go through with a point should Anderlecht defeat Benfica in Brussels. Laurent Blanc has guided his Ligue 1 leader on an unbeaten run in all competitions since taking over from current Real Madrid handler Carlo Ancelotti, while the capital outfit has not lost in the league since last March when it went down 1-0 at Reims. Captain Zlatan Ibrahimovic has scored 17 goals in his past 11 matches for club and country, including the third in the 3-0 win over Reims on Saturday which kept the team four points clear at the top in France. Olympiakos coach Miguel Torres has also built an impressive unbeaten league run of 29 matches without a loss since taking over in February as the team leads the Greek league and has not lost a domestic match away from home in 28 games, one short of its own national record.

Anderlecht (BEL) vs Benfica (POR): The Belgian leader is much in need of its first victory of the group stage and will take heart from its gutsy 1-1 draw at PSG on matchday four. It lost 2-0 in Lisbon the first time the teams met, but with the Portuguese picking up just one point from two games against Olympiakos, Benfica will be looking for maximum points to stay in touch with the top two spots and also solidify its chances of guaranteeing at least third and a spot in the next round of the Europa League. The teams met in the 1983 UEFA Cup final which was won by the Brussels' club, an occasion that saw current Benfica assistant coach Minervino Pietra turn out for the Lisbon side. Anderlecht is trying to reach the second round for the first time since 2000-01 while Benfica finished third in its pool last season before going on to reach the Europa League final where it was beaten 2-1 by Chelsea in Amsterdam.

Group D

CSKA Moscow (RUS) vs Bayern Munich (GER): The defending champion is Europe's top side and chasing what would be a record 10th consecutive Champions League victory when it visits a CSKA Moscow outfit which can only finish third at best. The Bundesliga front-runner is coming off a 3-0 thrashing off Borussia Dortmund on the weekend - the team it defeated in last year's final. That road victory extended its German league record to 38 matches unbeaten, although it will be wary of dropping points and potentially top spot in the group to Manchester City. Bayern has won three of its eight trips to Russian clubs in European action but has only lost once back in 2008, when it was sent packing at the semifinal stage of the UEFA Cup, beaten 4-0 by Zenit Saint-Petersburg. The German club has been rocked by a suspected mole at the Allianz Arena who has been revealing tactics ahead of matches to the German press, much to the fury of coach Pep Guardiola.

Manchester City (ENG) vs Viktoria Plzen (CZE): The 2012 English champion has qualified for the knockout phase for the first time following back-to-back wins over CSKA but needs to keep the pressure on Bayern, which is three points clear at the top heading into the penultimate matches. Manuel Pellegrini looked on as his side humiliated Tottenham 6-0 in Premier League action on Sunday and maximum points at home will set up a last-day finale in Munich. The Czech Republic side, looking for its first points and bidding to keep alive its Europa League prospects, faces a daunting task on its first trip to England at a City team which has lost just once at home in its past 22 European ties. Coming into this season's group stage, Plzen was riding a seven- match unbeaten run on its travels but is now trying to break a four-match European losing streak, the worst in the club's history.