Champions League Matchday 4: Who can punch knockout round tickets?

The UEFA Champions League returns on Tuesday and Wednesday with half of the group stage complete. On Matchday 4, the group stages move beyond projections and begin to slot in the first round of qualifiers for the knockout rounds.

[Champions League: Follow Matchday 4 live | Scores and Schedule | Group Standings]

Group A

Real Madrid and Paris Saint-Germain predictably lead the group, and the two super clubs meet with the hopes of providing more excitement than the 0-0 draw that took place in Paris on Matchday 3. Shakhtar Donetsk still has no points, and Malmo has already suffered defeats against both Real Madrid and PSG. A win for either Real Madrid or PSG on Tuesday would likely secure top spot in the group. Another draw would likely make goal differential the deciding factor.

UEFA Stat: Real Madrid has only allowed four goals in 13 matches this season.

Group B

All four teams are alive in Group B, but Wolfsburg leads with six points. An away win for Wolfsburg over PSV Eindhoven on Tuesday would all but secure passage to the knockout rounds. Manchester United and CSKA Moscow are both level on four points, so the Red Devils can gain a much-needed advantage over their closest rivals with a win at Old Trafford. Unfortunately for United, it has played its last three matches to 0-0 draws, including 120 minutes against lower-league Middlesbrough in the Capital One Cup. Contrary to the public outcry, Man United's inability to score is not entirely Wayne Rooney’s fault, but the 30-year-old has yet to score in the group stage this season.

UEFA Stat: Manchester United has drawn its last four games, including three straight 0-0 results, which is the Red Devils’ longest 0-0 streak since 2005.

Group C

Predictably, FC Astana of Kazakhstan is having a tough time adjusting to life in the Champions League. Apart from earning a surprise draw with Galatasaray, Astana has suffered two defeats, including a 4-0 drubbing to Atletico Madrid on Matchday 3. Astana is the first Kazakh team to make the Champions League group stage, so even one point after three matches is nothing to be ashamed of. With Atelti traveling to Kazakhstan on Matchday 4, the Spanish club can maintain its status at the top of Group C with a victory. Galatasaray beat Benfica 2-1 in Istanbul on Matchday 3, and a repeat of that result on Matchday 4 would push the Turks above Benfica. However, Tuesday’s game taking place under the hostile floodlights in Portugal should make a repeat result far less likely for the visitors.

UEFA Stat: Atletico Madrid has only conceded eight goals in 13 matches across all competitions this season.

Group D

Referred to as the “Group of Death” before the start of the group stage, Borussia Moenchengladbach has struggled to keep up with Sevilla, Manchester City and Juventus. The Italian champions have struggled domestically but remain unbeaten in Europe with two wins and a draw to sit atop their group. A trip to Germany on Matchday 4 provides Juventus the opportunity to guarantee a place in the knockout rounds if Manchester City manages a win against Sevilla in Spain. If results go wayward, though, any of these teams could end up out of Europe altogether.

UEFA Stat: Sevilla has won its last 10 European home fixtures at the Ramon Sanchez Pizjuan Stadium.

Group E

Without Lionel Messi, Barcelona has managed to earn domestic and European results by relying heavily on Neymar and Luis Suarez. While Barca is top of its group and should easily qualify for the knockout rounds, Bayer Leverkusen, BATE Borisov and AS Roma are only separated by two points with the Italians surprisingly sitting bottom of the group. On Wednesday, Roma can jump up to second place with a victory over Bayer Leverkusen at the Olimpico, provided that Barcelona can beat BATE at the Camp Nou. On Matchday 3, Roma and Bayer split eight goals in a thrilling game that proved to be the standout match of the round. A repeat of that 4-4 draw would be a welcome sight.

UEFA Stat: Barcelona has qualified for the last 16 of the Champions League for 11 straight seasons.

Group F

Can Arsenal stun Bayern Munich again? The Gunners travel to Germany without Theo Walcott and Alex Oxlade-Chamberlain available, so their chances are longer than a fortnight ago. Should Arsenal fall to beat Bayern, which is expected, it would pray for help from Dinamo Zagreb against Olimpiacos. As it stands, an Arsenal defeat and a home victory for Olimpiacos on Wednesday would put the Greeks six points clear of the Londoners with only two matches to play. A draw or a Zagreb victory gives the Gunners’ their best chance at advancing to the knockout rounds, though a trip to Greece still awaits Arsenal on Matchday 6.

UEFA Stat: Olivier Giroud has scored six goals in his last six games for club and country, while Robert Lewandowski has scored 23 goals in 20 games for club and country this season.

Group G

Murmurs out of Stamford Bridge claim Chelsea manager Jose Mourinho only has a couple games to turnaround the Blues’ horrendous start to the season. No coincidence, Chelsea’s next match is a crucial Champions League home tie against Dynamo Kiev. A home victory would put Chelsea back in the driver’s seat for qualification to the knockout rounds. FC Porto currently leads the group, and the Portuguese giant should make easy work of Maccabi Tel Aviv, a team that has lost all three of its Champions League games thus far. A Chelsea victory would put the Blues two points ahead of Kiev with a trip to Tel Aviv and a home match against Porto remaining.

UEFA Stat: Chelsea has lost six of 11 Premier League matches this season, which is already more defeats than the Blues suffered in all of the 2014-15 season.

Group H

Hulk is smashing Group H. After three matches, the Brazilian has three goals, and consequently, Zenit Saint Petersburg has three wins. Zenit is the only team with a perfect record in the Champions League group stages after three rounds of play, so the Russians are the safest bet to make the final 16. Barring a major collapse, Valencia should join Zenit as the second team out of Group H. Gent and Lyon each only have one point at the halfway mark, so only a minor miracle would see those sides steal a spot off Zenit or Valencia.

UEFA Stat: Valencia has won six of its last nine away games in Europe.

Shahan Ahmed is a soccer columnist for Yahoo Sports. Follow Shahan on Twitter: @ShahanLA and @perfectpass