The Champions League campaign rumbles on this week, and with it, a new set of storylines to watch as Europe's top sides continue to pursue the most coveted club trophy on the continent. Below, we look ahead to Matchday 4.
Several of Europe's biggest clubs, all of whom, to varying degrees, consider themselves perennial contenders for the Champions League crown this season, can clear the first hurdle this week by securing progression to the knockout stage.
Bayern Munich, Manchester City, Liverpool, Barcelona, and Juventus - a pantheon of the continent's most talented teams - can reach the last 16 with various result combinations. Meanwhile, Chelsea and Sevilla, both taking the pitch in Tuesday's early time slot, are heavy favorites to wrap up the top two places in Group E when they meet Rennes and Krasnodar, respectively. As is almost always the case in the Champions League, the cream is rising to the top in the opening round, leaving little room for surprises.
The Ronald Koeman era at Barcelona has been a slog thus far. Rumblings of discontent are growing in the Catalan capital, despite sitting top of a Champions League group that includes Juventus - Barca cruised to an impressive 2-0 win in Turin last month. Every step forward is invariably followed by a hiccup, with the latest setback, a rare league defeat to Atletico Madrid, dropping Barca down to 13th in the La Liga table. Thirteenth!
There are some mitigating factors - key injuries, in particular, are ravaging the squad at the moment - but the early-season struggles, combined with the dark cloud of Lionel Messi's disenchantment, have created a kind of apathy not associated with this footballing institution for quite some time. On paper, Tuesday's tricky trip to Dynamo Kyiv is winnable, but any slip-up and the hot seat Koeman finds himself on will become scalding.
It's now or never for Inter Milan. A frustrating 3-2 loss to Real Madrid in the Spanish capital earlier this month left the Italian side sitting bottom of a topsy-turvy Group B on two points from three games. Another defeat Wednesday, against the same opponents, and an early exit will beckon. "We play well but always make some mistakes," striker Lautaro Martinez said, perfectly summing up Inter's inconsistency.
On the bright side, Real Madrid aren't exactly setting the world alight. Zinedine Zidane's team has three wins in eight games and hasn't kept a clean sheet during that run, conceding 15 goals in the process. Worse yet, captain Sergio Ramos is out with a hamstring injury, while talismanic forward Karim Benzema will also miss the contest with an adductor issue. Real Madrid are eminently beatable right now. Will Inter avoid tripping over their own feet and take advantage?
There's still room on the Youssoufa Moukoko hype train, but the caboose could be full by week's end. The Borussia Dortmund wunderkind, 16, will become the youngest player to ever feature in the Champions League if he makes an appearance against Club Brugge on Tuesday. He already owns that same Bundesliga record after coming off the bench in Saturday's win over Hertha Berlin, making his league debut the day after his 16th birthday.
Moukoko, who racked up an absurd 13 goals in just four games for Dortmund's Under-19 team this year, is looking to break Celestine Babayaro's benchmark as the Champions League's youngest debutant. The Nigerian left-back established the current record in 1994 when, at 16 years and 87 days old, he started for Anderlecht in the group stage. Moukoko will surely hope for a better outcome if he does play; Babayaro was sent off 37 minutes into his historic debut.
Sitting in a precarious position in Group H, last season's finalists head into Tuesday's tilt with RB Leipzig knowing that another defeat to the German side would likely prove a fatal blow to their chances of reaching the knockout round. In no uncertain terms, it would be a disaster for a club that is singularly focused on capturing Europe's top prize for the first time.
To have any hope of doing that, Paris Saint-Germain need Kylian Mbappe to end his Champions League scoring funk. The all-world French forward, now fit again, is on a barren run of seven games in the tournament. He's had no such trouble in Ligue 1 - Mbappe's the top scorer in the league - but, for whatever reason, that form hasn't yet translated. If he gets blanked again Tuesday, PSG's season could very well be in tatters before we hit December.
English clubs chugging along: Heading into the week's slate, all four Premier League teams - Chelsea, Liverpool, Manchester City, and Manchester United - sit top of their respective groups. Barring something boneheaded from the latter, which is possible, they'll all feature in the knockout round this season. Could we be cycling back to the previous decade when English clubs were a permanent fixture in the tournament's latter stages? If the past few years are any indication, maybe we're trending that way.
Atalanta need to bounce back: After gatecrashing the tournament last year - and winning countless plaudits along the way - Atalanta were expected to kick on and continue ruffling the feathers of Europe's hierarchy. It hasn't quite worked out that way, though. They have just one win in their last six games across all competitions, a run that included getting blasted into oblivion by Liverpool at home. Up next? Just the small matter of a trip to Anfield, where the Reds are virtually invincible. Gian Piero Gasperini needs to find some of last season's magic, and quickly.
Another record in sight for Bayern: The holders, currently on an unprecedented run of 14 consecutive victories in the competition, have another benchmark firmly in sight. Bayern Munich have notched 12 goals through their first three matches - all wins - in Group A. The Champions League standard for tallies in the group stage is 25, set by PSG in 2017-18. Bayern came one shy of matching that total last season. Can they go one (or two) better this time around?