Every once in a while in the Champions League group stage, a team that was viewed as a potential contender gets knocked out in the group stage. Now, it's rarely ever a top-tier contender but often those second-tier teams that have a chance to make a darkhorse run to the final and maybe even win it. 

We saw it with Atletico Madrid last season and Manchester United in the 2015-16 season, and it's usually the product of a tricky group. And with the changes we've seen to the draw structure, we've gotten some really difficult groups this season that could see some teams surprisingly crash out. Here are three teams that, while they should move on, seem the most likely to slip up.  

Manchester United: In Group H, this is more about United than its scheduled opponents. Jose Mourinho's squad should get six points from the matches against Young Boys, and they'll be the underdog against Juventus. So the team's main competition for second place will likely be Valencia, a team that is somewhat similar to United when it comes to the talent on the roster but lacking consistency early on. It's one of those things where, if the Red Devils were to lose at Mestalla and slip up at home and draw Valencia, then they'll likely be headed for the Europa League.

Atletico Madrid: In Group A, this would be the product of a tough group. Atleti, which hasn't been sharp early on this season, has to face Borussia Dortmund and Monaco, along with Club Brugge. Dortmund and Monaco are two teams potent in attack to counter that Atletico defense, and it wouldn't be a surprise if this team finishes anywhere between first and third. We saw Atletico finish third last season in a group with Roma and Chelsea, and the result might be the same this time around. The issue with Atletico early on has been an inconsistency in front of goal, scoring three goals in its first four games. 

Liverpool: Yes, the Reds made it all the way to the Champions League final and there's no doubt they are expected to advance to the round of 16, but this is all about who they play. Red Star Belgrade shouldn't cause any problems, but having to open up against Paris-Saint Germain and then have to go to Napoli, there's a chance this team could potentially have zero points after two games. Now, with a defense that has improved, especially with Alisson in goal, they are well prepared to combat what PSG and Napoli can do in attack. But considering that PSG has scored at least three goals in every game and Napoli's ability in the final third, something has to give. On a more positive note, Napoli has struggled a bit defensively and will likely have trouble on the wings against Liverpool. Consider PSG the group winner with Liverpool and Napoli battling it out for second place.

Have a look at where those three rank in our latest installment of Power Rankings:

World Club Soccer Power Rankings

Previous rankings: Sept. 4Aug. 28 Aug. 23 | Aug. 15 | Preseason rankings



Bayern Munich (GER)  


A come-from-behind win over Bayer Leverkusen. Bayern Munich has scored three goals in each of the past three games. This team is rollin'.


Liverpool (ENG)  


Impressive 2-1 win over Tottenham at Wembley. The defense is improved and that makes this team a contender to win it all.

Juventus (ITA)


Cristiano Ronaldo finally scored! And he did it twice. Great timing for them to get their star going and filled with even more confidence. As for Douglas Costa, what was he thinking?


Barcelona (ESP)


Playing at Anoeta has been tough for this team in the past, but they come back a get a 2-1 win. Another impressive result and Ousmane Dembele kept his fine form going by scoring. 


Paris Saint-Germain (FRA)


Another bunch of goals and another win. Just what we expect from this team almost every time they play. Is this the season it captures that elusive Champions League title?


Manchester City 


A 3-0 victory over Fulham to bounce back from a draw to the Wolves. Creating so many chances in final third but just as step behind PSG.


Tottenham (ENG)


Outclassed by Liverpool. Not enough creative quality in the final third despite the possession. 


Real Madrid (ESP)


Not sharp at Athletic Bilbao. At times it feels like this team needs better players.


Chelsea (ENG)


A contender to win the Premier League. Consistent as can be, and nobody is playing better in the league than Eden Hazard.


Atletico Madrid (ESP)


Struggled at home against Eibar. Not the vibes you want with a trip to Monaco midweek.


Napoli (ITA)


Fine result to beat Fiorentina 1-0. The defense looked improved and that's a good sign, considering how tough that Champions League group is.


Borussia Dortmund (GER)


Young and hungry. You know things are going well when you can even get Paco Alcacer to find his scoring touch.


Manchester United (ENG)


Crazy to think Manchester United winning at Watford was a statement win, but it was up against a team that looked much better to start the season. With back-to-back wins, is this team turning the corner?


Arsenal (ENG)


Three wins in a row and improving in attack. As for that goal from Granit Xhaka? What a world-class strike.


Roma (ITA)


Two-game slump where the defense has struggled mightily. Going to need to invest in a better goalkeeper come Jan. 1. 


Boca Juniors (ARG)


Toughened out a win at Argentinos Juniors over the weekend to stay near the top of the table. Big games coming up against Cruzeiro and the Superclasico vs. River Plate.


Watford (ENG)


Fought well against Manchester United, but they just couldn't get a result in the end. Some big matches coming up where we will learn plenty. 


Inter Milan (ITA)


As inconsistent as they come. Feels as if this team isn't capable of finishing second in its tough Champions League group with Barcelona, Tottenham and PSV.


São Paulo (BRA)


Temporarily at the top of the table in Brazil after a quality 0-0 draw against Santos. 


Cruz Azul (MEX)


Still in first place in the league but suffered their first loss, 2-0 to Necaxa. For the first time all season, the defense just wasn't there.


Internacional (BRA)


Beat rival Gremio 1-0 last week before facing Chapecoense on Monday. A contender to win the league, and they can go top of the table again on Monday. 


Racing (ARG)


Four wins from five to start the league and now sit top of the table. Just two goals conceded, grabbing a 1-0 win at Lanus on Sunday.


Gremio (BRA)


Lost their rivalry match to Internacional but did beat Parana 2-0 on Saturday. Huge Copa Libertadores match is up next. 


Borussia Mönchengladbach (GER)


Huge 2-1 win over struggling Schalke. The patience and execution in final third has been superb. 


Bournemouth (ENG)


Three Premier Leagues wins in five matches after winning 11 all of last season. When will this cease to be surprising?

Biggest movers: 
Arsenal (+3), Inter Milan (-4). 
Teams knocked out of the top 25 this week: Valencia (ESP)
Honorable mentions: Celta Vigo (ESP), Atletico Tucuman (ARG), Benfica (POR), Galatasaray (TUR)

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