Milan: When Barcelona plays Tottenham on Wednesday it will bring back fond memories for the Catalan soccer giant.

With continuing uncertainty over when the rebuilding of White Hart Lane will be finished, Tottenham is still playing its home matches at Wembley — England's national stadium.

Barcelona won the Champions League title at Wembley in 2011, beating Manchester United 3-1.

Surprisingly it has triumphed in Europe just once since then — in 2015 — highlighting the failure of Lionel Messi and its host of other stars to fulfill their potential fully in the Champions League.

Moreover, its bitter rival Real Madrid has won the title four times in the same period.

Another Spanish side in action, Atletico Madrid, has lost two of the past five finals — being beaten both times by Real Madrid. It hosts Club Brugge.

Real Madrid's final success last year came against Liverpool, the English power that this week travels to Napoli.

Here is a look at the four Champions League groups on Wednesday:

GROUP A

Atletico Madrid has only lost once in nine matches across all competitions this season.

It won its Champions League opener 2-1 at Monaco and is coming off a satisfactory 0-0 draw at Real Madrid, extending its run in La Liga to six consecutive visits to the Santiago Bernabeu without a loss.

Goalkeeper Jan Olbak has been particularly miserly of late, having not conceded a goal in three successive matches.

Borussia Dortmund will be in an even more buoyant mood when it hosts Monaco, after seizing the Bundesliga lead from Bayern on Saturday.

While former midfielder Sebastian Kehl said it was "too early" for a title challenge, fans are dreaming of a repeat of the glory days under former coach Juergen Klopp, who led the side to back-to-back Bundesliga titles before the Champions League final in 2013.

They will also be hoping to get their revenge, after a rampant Monaco side scored six goals in two games against the German side when the two met in the Champions League quarterfinals in 2017.

The current Monaco outfit is a pale imitation, however, and Leonardo Jardim's side heads to Dortmund bereft of confidence and unable to score, having suffered two straight defeats.

GROUP B

Tottenham and Barcelona are meeting for only the third time in a competitive match, having previously faced each other in the semifinals of the European Cup Winners' Cup when the Catalan club advanced.

Facing Barcelona is more familiar territory for Tottenham manager Mauricio Pochettino, who won only one of nine encounters while in charge of Espanyol.

While Barcelona rested Lionel Messi on the weekend, Tottenham had a squad depleted by injuries against Huddersfield but Harry Kane did score his first double of the season in the Premier League victory.

Tottenham will hope goalkeeper Hugo Lloris recovers from a thigh problem and playmaker Christian Eriksen recovers from a stomach injury for the visit of Barcelona. Midfielder Dele Alli has already been ruled out with a hamstring injury.

Barcelona will be without the injured Sergio Roberto as well as defender Samuel Umtiti, who is suspended following his sending-off during the 4-0 win over PSV Eindhoven, when Messi scored a hat trick.

Tottenham lost its opener to Inter Milan 2-1 after the Italian side scored two late goals to complete a dramatic comeback.

That reignited Inter's season, with Luciano Spalletti's side winning its next three Serie A matches and it will be hoping to continue that run at Eindhoven.

GROUP C

Liverpool goalkeeper Alisson knows just how tough it will be at Napoli. Seven months ago before moving to England, Alisson was part of the Roma side that won 4-2 in Napoli when he had to save 11 of 13 shots on target.

"It was one of the toughest games of the season for us in Serie A," Alisson recalled ahead of the trip back to Italy.

However, Napoli has not shown the same attacking flare under Carlo Ancelotti as it did under Maurizio Sarri — as exemplified in the scoreless draw at Red Star Belgrade in the group opener. It lost 3-1 to Juventus in the Italian league on Saturday.

Although Alisson conceded twice in his first Champions League game with Liverpool two weeks ago, a stoppage time goal from Roberto Firmino sealed a 3-2 win over Paris Saint-Germain at Anfield.

"To beat a great team like PSG fills you with confidence," Alisson said. As does still being unbeaten after seven games in the Premier League.

A daunting trip to PSG has been made harder for Red Star Belgrade, which will be without fans after trouble in the second leg of its playoff at Salzburg.

Red Star supporters have been banned for the club's first two away matches by UEFA, and the Serbian team was fined €30,000 ($34,700) for damages caused, for the throwing of objects, and for the setting off of fireworks.

Considering PSG is heavy favorite to beat the team from Serbia at Parc des Princes, PSG coach Tuchel may be tempted to pick young players like defenders Colin Dagba and Stanley N'Soki, and forward Moussa Diaby.

They have done well when selected this season, but Tuchel also knows PSG needs to bounce back after its opening defeat.

Most likely, stars Neymar, Edinson Cavani and Kylian Mbappe will start the match and Tuchel will look to bring the youngsters on if and when the game is safe.

GROUP D

After comfortably beating Lokomotiv Moscow 3-0, Turkey's Galatasaray knows it can take control of the group with another victory at Porto.

Badou Ndiaye is unavailable after his red card in that match, while fellow midfielder Emre Akbaba broke a metatarsal in Friday's win over Erzurumspor and will be out for some six weeks.

Porto also lost an important player to injury as star striker Vincent Aboubakar ruptured the anterior cruciate ligament in his left knee during Friday's win over Tondela.

Galatasaray is without a victory on the road in Europe in 13 matches, since a 3-2 success at Schalke in the Champions League round of 16 in March 2013.

Porto drew its opener against Schalke, which ended its five-game losing start to the Bundesliga with a 1-0 win over Mainz on Saturday and will hope to kick on from there at Lokomotiv Moscow.

Lokomotiv looked weaker than other recent Russian champions in its opening loss to Galatasaray and is struggling in the Russian league, with three wins from nine games.

Of its summer signings, striker Fyodor Smolov was suspended for the Galatasaray defeat and has now injured his shoulder, while coach Yuri Syomin has struggled to fit 2014 World Cup winner Benedikt Hoewedes into his system.