Champions League: What Can Be Decided on Matchday Four?

The Champions League returns in midweek following a three-week absence, with an intriguing set of matchday four fixtures for us to feast on.

The reverse encounters in the group stages get underway on Tuesday evening with qualification into the knockout phase already beckoning for some sides, while others may succumb to elimination.

Here's everything that can be decided in the Champions League group stages on matchday four.

1. Group A

Matchday Four Fixtures: Atletico Madrid (2pts) vs Lokomotiv Moscow (2), Bayern Munich (9) vs RB Salzburg (1)

The holders' march towards back-to-back European glory will continue with a victory over Red Bull Salzburg.

A draw might even be enough for Hansi Flick on Wednesday night for if Lokomotiv Moscow fail to beat Atletico in the other fixture.

2. Group B

Inter (2) vs Real Madrid (4), Borussia Monchengladbach (5) vs Shakhtar Donetsk (4)

Perhaps the most competitive group out of the lot, with Marco Rose's enterprising Borussia Monchengladbach emerging as the surprise leader.

Nobody can either qualify or be eliminated on matchday four.

It's all very much to play for at the halfway mark.

3. Group C

Olympiakos (3) vs Manchester City (9), Marseille (0) vs Porto (6)

Another walk in the park for Pep Guardiola's City after collecting maximum points at the halfway point in a pretty tame group.

City need a point in Greece to progress, while Marseille have to avoid defeat to second-place Porto to keep their faint hopes alive.

4. Group D

Liverpool (9) vs Atalanta (4), Ajax vs Midtjylland (0)

Jurgen Klopp's Liverpool have been mightily impressive thus far and will be looking to replicate their 5-0 trouncing of Atalanta when they meet again on Wednesday night.

Victory against La Dea confirms their place in the knockouts, with a draw being enough if Ajax fail to beat Midtjylland - who'll be eliminated if they lose - in Amsterdam.

5. Group E

Rennes (1) vs Chelsea (7), Krasnodar (1) vs Sevilla (7)

Chelsea can book their place in the last 16 providing Sevilla get a result in Krasnodar on Tuesday night.

Should Julen Lopetegui's side grab all three points in Russia, the Blues will only need to avoid defeat to Rennes to progress.

Wins for the current top two will see both advance on matchday four.

6. Group F

Borussia Dortmund (6) vs Club Brugge (4), Lazio (5) vs Zenit (1)

With three sides in the mix for qualification, nothing can be decided on Tuesday.

However, should Zenit fall to defeat in Rome and Dortmund beat Club Brugge, the Russians could be eliminated.

7. Group G

Dynamo Kyiv (1) vs Barcelona (9), Juventus (6) vs Ferencvaros (1)

Wins for Barcelona and Juventus will see the pair of fading European powers through, with a draw being enough for the Catalans if the Bianconeri avoid defeat.

Ferencvaros and Dynamo Kyiv need practically every result to go their way to qualify.

8. Group H

Manchester United (6) vs Istanbul Basaksehir (3), Paris Saint-Germain (3) vs RB Leipzig

The tightly-knit nature of this group means nowt can be decided on Tuesday night.

With head-to-head records determining placings, United could find themselves outside of the top two should they lose again to Istanbul Basaksehir.