UCL PREVIEW: Liverpool, Atletico and Real Madrid can QUALIFY for Champions League knockout stages by avoiding more shock slip-ups

A host of top clubs are facing crunch time in the Champions League ahead of Tuesday's fixtures as Atletico Madrid, Real Madrid and Liverpool bid to secure early progress while knowing that a setback could threaten their ambitions.

As the Champions League group stage moves towards its conclusion, several of Europe's elite clubs must navigate potential banana skins today, knowing that a slip-up could be critical to their hopes of advancing to the competition's knockout stages.

Injury-ravaged Liverpool could end the night in the knockout stages or out of the qualification spots in Group D, which would surely prompt another tetchy press conference from coach Jurgen Klopp.

Real Madrid and Atletico Madrid could also find their places in the competition in serious jeopardy should they fail to win.

So how do things stand for some of Europe's most under-pressure sides as they battle to qualify?

Group A - Atletico Madrid vs. Bayern Munich

Despite impressive domestic form that has seen them concede just twice in the league and stand well-placed to leapfrog leaders Real Sociedad, Diego Simeone's Atletico side have been unusually ineffective in Europe this season.

Atletico have earned five points from four Champions League games thus far, scoring four goals and recording a solitary win in the competition, and they now face the unenviable task of welcoming a rampant Bayern Munich team to the Wanda Metropolitano knowing that defeat could leave their fate out of their hands ahead of the final group fixture.

Lokomotiv Moscow, who are two points behind them in the table, are at home to bottom side RB Salzburg, and they know that a win could consign Atletico to third place and leave them reliant on Munich doing them a favor against the Russian side in next week's matches. 

Atletico's ambitions of avoiding such a scenario will be buoyed by the absence of Munich's outstanding shot-stopper, Manuel Neuer, and goal machine Robert Lewandowski, both of whom are expected to be rested for the side who have already cantered to a comfortable group victory with four wins out of four.

Bayern were 4-0 victors in the reverse fixture and a similar result would be damaging for the hosts, who have been losing finalists twice in the last seven seasons. 

Group B - Shaktar Donetsk vs. Real Madrid

If the red and white half of Madrid hasn't exactly been enjoying the Champions League journey so far this season, the same can be said of their city rivals Real Madrid.

Zinedine Zidane's men are currently second behind surprise Group B leaders Borussia Monchengladbach, and a point in Donetsk would ensure their progress - although anything less than three points would also guarantee that they would have to beat Gladbach at home next week to win the group.

In a far from ideal start to the season, Madrid have been hampered by an unusually porous defense, shipping 12 goals in 10 domestic matches and seven in four Champions League games.

Luckily for Real, their Ukrainian opponents have been anything but efficient in front of goal themselves, scoring three times in the group so far. Shakhtar need to win to bring themselves level with the Spanish giants in second place, and three points could also guarantee them at least a Europa League place.

This is a high-stakes test. Madrid's shock 2-1 home defeat to Alaves at the weekend was hardly ideal preparation but Zidane knows that a win will secure his side's passage to the next round - so long, you feel, as their famously miserly defence resumes normal service.

Group D - Liverpool vs. Ajax

It may seem strange to some but, despite being top of their Champions League group with two games remaining, it isn't all plain-sailing at Anfield these days.

Only the most rose-tinted of Koppites would predict that this year's iteration of Liverpool will come close to repeating the heroics that have brought them the Premier League and Champions League titles during the past two years, and whether that is down to the incessant injuries plaguing Jurgen Klopp's team or a general loss of form is open to debate. 

The totemic defensive duo of Virgil van Dijk and Joe Gomez are long-term absentees, while goalkeeper Alisson and the talismanic Mohamed Salah have also been out. Losing players of that caliber would be a blow to anyone, but it has deprived Liverpool of the spine of their team. 

Regardless of the reasons, Liverpool have seemed unusually frail so far this season (by their own standards, at least) and will welcome an Ajax team to Anfield who know that a win would see them leapfrog the Merseysiders.

The worst-case situation in this particular scenario would be for Inter Milan to win three points in their game with whipping boys Midtjylland. That would see Liverpool drop to third place and seriously threaten their European ambitions, likely producing another angry Klopp polemic about fixture congestion along the way.

The increasingly irritable manager would doubtless prefer to concentrate on the positives. Victory would be the perfect riposte to Liverpool's surprise home defeat to Atalanta and would secure their place in the knockout stages for another season, meaning Klopp could rest players when they travel to Midtjylland next week.