10 key takeaways from this week's Champions League action

After every Champions League matchday, theScore highlights 10 marquee takeaways from Europe's preeminent club competition.

Courtois' form demands Areola chance

A deafening chorus of whistles at the Bernabeu isn't exactly a conclusive appraisal of a player. Real Madrid fans can be fickle, but on Tuesday, the jeers directed at Thibaut Courtois were merited. Sure, Sergio Ramos and Raphael Varane were M.I.A. on Club Brugge's opener, but there's no escaping how clumsy the gaunt Belgian is.

Courtois has conceded 13 goals with two clean sheets in eight matches this term. Keylor Navas - who was shipped to PSG - needed 19 outings to yield the same number. That's now 81 goals on Courtois' watch in 58 matches. Apparently Courtois had an upset tummy, prompting a swap for Alphonse Areola at the half. It's time Zinedine Zidane considers a permanent switch.

Atalanta's Zapata ready for the biggest stage

It's strange Europe's biggest clubs weren't linked with Atalanta's Duvan Zapata this past summer. The Colombian had a career-defining year, finishing second in the Serie A scoring charts with 23, and this season, he's joint-tops on five. Against Shakhtar Donetsk, he scored La Dea's first-ever European goal.

Even with Atalanta attacking from wide positions against the Ukranians - with Papu Gomez thriving on the right before shifting into a central role upon Luis Muriel's second-half introduction - Zapata's work rate was stellar. Frighteningly robust and deceivingly swift, Zapata has proved he deserves a big-time transfer to a club with a dearth of No. 9 options.

Chelsea's undervalued talisman: Willian

On Wednesday in France, Chelsea were perilously close to completing the first two matches of group play with a sole point. Then, Willian happened, and for a young squad hampered by a transfer ban following Eden Hazard's departure, the Brazilian's continued contributions are massive.

Willian's astounding 78th-minute strike cemented a 2-1 victory over plucky Lille, and since making his Champions League debut for the Blues in 2013, no player has been directly involved in more goals than the generously maned attacker. That's now 10 goals and five helpers for the versatile 31-year-old. And people wonder why Christian Pulisic can't get in the team.

Takumi Minamino: A star is born

Salzburg striker Erling Haaland was in the spotlight heading into Wednesday's clash at Anfield, and for good reason. The goal-scoring Norwegian youngster bagged a first-half trio in the Group E opening battering of Genk. Against Liverpool, another star was born: Takumi Minamino.

The 24-year-old 19-time capped Japanese international was unplayable, and Minamino was arguably the best player on a pitch littered with world-class stars. He was a threat on the break courtesy of sneaky pace and elite vision, hitting a deft volley for Salzburg's second before finding substitute Haaland for the visitors' third of a surreal three-goal comeback. Cue the transfer rumors.

Real should consider Hakimi recall

Marcelo is in decline, Ferland Mendy is unproven, and Nacho - who suffered an MCL injury versus Brugge - is better suited in central defense than as a full-back. Despite seemingly endless resources and a trio of options, Real Madrid's best left-back might be plying his trade in the Bundesliga.

In the second term of a two-year loan at Borussia Dortmund, 20-year-old Moroccan left-back Achraf Hakimi is making a case for a future in Spain. The 20-year-old scored both of BVB's goals versus Slavia Prague, the first courtesy of a blistering run down the right before a cut-in and left-footed finish, the second a surge down the left that displayed his versatility. What a player.

Lewandowski in the form of his life

Perhaps it's his conventional, ordinary appearance, or maybe it's the proletarian-like industry and sublime technique that makes Robert Lewandowski easy to overlook. Bayern Munich pluck talent from rivals and sleepwalk to titles, so it's understandable why Lewandowski's tenure is not more celebrated.

This season, Lewandowski has been immense. The 31-year-old has scored in each of his last 10 matches, including Tuesday at Spurs. The Polish star scored twice in Bayern's bludgeoning of Tottenham, and with 10 goals through six in the league and three in Europe, Lewandowski is set to better a career-best 39 goals over the two competitions. Also, his touch is absurd.

Defensive miscues sink Spurs

On the topic of a Tottenham side that shipped seven goals at home for the first time in any competition, while Serge Gnabry and Lewandowski were unplayable, Spurs didn't help their own cause. Serge Aurier's awful showing was a symbol of a defensive unit out of its depth.

Dire defending led to Lewandowski's first goal, and Harry Winks gave the ball away 30 yards from his own goal for Gnabry's second. A flat-footed Aurier and off-the-pace Jan Vertonghen were at fault for Gnabry's third, and minutes later, Toby Alderweireld's daft pass was picked off by Thiago for Lewandowski's second before Gnabry made it 7-2 (above).

Preview of post-Mertens Napoli lacks gusto

Napoli got a glimpse at what life after Dries Mertens might resemble, and it wasn't great. The Belgian's terms lapse in the summer, and against Genk, Mertens started on the bench as Arkadiusz Milik led the line. Milik spoiled four quality chances after missing the target five times.

At the interval, Napoli boasted an Expected Goals (xG) of 2.48 thanks to Milik's wastefulness, though once Mertens came on in the 58th minute for Eljif Elmas to the left of the towering Pole, Napoli's movement in attack improved. Milik deserves the benefit of the doubt after suffering two significant injuries, though that window is closing, especially if Mertens leaves next summer.

Selfless Sarabia the key to PSG success

Save for Take Your Kid To Work Day candidate Eric Choupo-Moting, Thomas Tuchel will need to appease a stacked attack featuring Neymar, Edinson Cavani, Kylian Mbappe, and Mauro Icardi. Against Galatasaray, Icardi opened his account thanks to the selfless play of Pablo Sarabia.

Newcomer Sarabia found a surging Icardi, and instead of firing at Fernando Muslera, he put it on a platter for the Argentine. For all the egos in his squad, Tuchel will benefit most from the altruistic efforts of Sarabia, Idrissa Gueye, and Ander Herrera. In 70 minutes, Sarabia boasted 88% pass completion. Decent return from an unlikely source.

Doubting Suarez is a fool's errand

Barcelona has had an underwhelming campaign by their lofty standards, and with Lionel Messi recovering from injury, the attack has been a popular target of derision. Luis Suarez is as culpable as any, and heading into the visit from Inter, the Uruguayan's residency at the Camp Nou came into question.

Few players are capable of transforming a match after a spell of anonymity like Suarez. Before equalizing with a nimble volley in the 58th minute, Suarez had 26 touches. Only goalkeeper Marc-Andre ter Stegen (15) and second-half sub Arturo Vidal (8) had fewer. Then, 26 minutes and 11 touches later, Suarez iced the fixture with a sublime left-footed finish. Doubters beware.