A look at what's happening around the Champions League this week:
TOTTENHAM WAITING ON KANE
Tottenham is anxious about the fitness of leading scorer Harry Kane ahead of Real Madrid's visit on Wednesday in a game that could decide the winner of Group H.
The teams are equal with seven points after three matches, having drawn 1-1 at the Bernabeu two weeks ago, but this time Spurs might be without Kane.
The England striker missed Tottenham's 1-0 loss to Manchester United on Saturday with a hamstring injury and his absence resulted in a limited attacking display from Mauricio Pochettino's lineup.
Madrid is experiencing domestic struggles of its own. It fell eight points behind La Liga leader Barcelona after a surprising 2-1 loss to Girona on Sunday.
However, both Tottenham and Madrid can play with the comfort of a six-point advantage over Borussia Dortmund and Apoel, and either team can advance to the knockout stage if it wins.
Manchester United and Manchester City will be aiming to extend their perfect group stage records. A win for United against Benfica at Old Trafford on Tuesday could secure progression from Group A, while City can do the same with a win at Napoli in Group F on Wednesday.
Chelsea and Liverpool also sit atop their groups, though with less of a cushion. The Blues can take a big step toward qualification on Tuesday just by avoiding defeat at Roma in Group C, while Liverpool must cash in on its Group E clash against NK Maribor at Anfield on Wednesday, with sterner tests to come from Spartak Moscow and Sevilla.
By Sam Johnston in London
Unbeaten Paris Saint-Germain has scored nearly 50 goals this season and will be confident of sealing its place in the knockout stage with a win against Anderlecht.
Having lost the home game 4-0 two weeks ago, Anderlecht has a genuine reason to be fearful on Halloween at Parc des Princes in Tuesday's Group B match. PSG has won its three group games without conceding a goal and, at the attacking end, Edinson Cavani is in scintillating scoring form.
Cavani's two goals against Nice last Friday took his tally to 15 from 13 games overall, including four in the Champions League.
Monaco was last season's free-scoring team in France, winning the league in style and reaching the European Cup semifinals with an attacking brand of football. But coach Leonardo Jardim's team would be happy with any win away to Besiktas on Wednesday. It's a must-win game in Istanbul for Monaco, which is at bottom of Group G with just one point. Besiktas could advance to the knockout stage with a win.
Monaco has won both its league games since losing 2-1 at home to Besiktas. With his new-look lineup finally looking like it's starting to gel, and top scorer Radamel Falcao likely to return after being rested Saturday, Jardim has some cause for optimism.
By Jerome Pugmire in Paris.
PRESSURE ON ATLETICO
While Barcelona and Real Madrid remain in comfortable positions to advance to the knockout stage, Atletico Madrid and Sevilla enter the week needing good results to keep their hopes alive.
Atletico hosts Qarabag on Tuesday bidding for its first win in Group C, which has Chelsea and Roma at the top. Atletico, after a disappointing league draw against Villarreal, trails Roma by three points and Chelsea by five.
Sevilla is coming off a demoralizing 5-1 loss to Spartak Moscow in Group E, but it gets a shot at revenge when the Russian team comes to Seville on Wednesday. The Spanish club has four points, one less than both Spartak and Liverpool.
Barcelona, which leads Group D with nine points from three matches, plays at last-place Olympiakos.
By Tales Azzoni in Madrid.
REVENGE IN NAPLES
This could be Napoli's year in Serie A, and it might be affecting its Champions League campaign.
After six years of domination by Juventus, the Italian league title is a tight contest. Napoli beat Sassuolo 3-1 on Sunday to remain three points ahead of Juventus atop the standings.
It was a 10th win in 11 league matches for Maurizio Sarri's side, which has only dropped points in a draw against Inter.
Next up is the visit of Group F leader Manchester City in the Champions League on Wednesday, and Sarri admits his players are focusing more on domestic matters than Europe's elite club competition.
"It's the most important club competition in the world, so being a part of it is something to be proud of," Sarri said. "It's also natural that in the minds of the players they focus more on the competition they've got a better chance at, but we must be eager to challenge ourselves against the best and right now Manchester City is the best side in the world."
Juventus is away at Sporting Lisbon on Tuesday as it aims to keep within three points of leading Barcelona in Group D.
By Daniella Matar in Rome.
Jupp Heynckes is bidding to keep his perfect record since returning to Bayern Munich when his team plays Celtic in Glasgow on Tuesday.
Carlo Ancelotti was dismissed after Bayern was humbled by Group B leader PSG but, in his fourth spell with the German champions, Heynckes has restored order.
Bayern beat Celtic two weeks ago in Munich and a repeat will likely ensure progression to the knockout stage.
The path to the round of 16 is not so simple for Leipzig in Group G. The Champions League debutant got its first victory in the competition two weeks ago against Porto, taking its tally to four points.
But with Besiktas out of sight with nine points and last season's semifinalist Monaco lurking, there is pressure on Leipzig to produce a positive result from its return fixture with Porto.
Borussia Dortmund's chances are slimmer as it chases its first Group H win.