Cristiano Ronaldo helped Real Madrid win "La Decima" last season -- the club's 10th triumph in Europe's premier competition. No side has retained the Champions League title since its change in format in 1992.
Real deal —
Cristiano Ronaldo helped Real Madrid win "La Decima" last season -- the club's 10th triumph in Europe's premier competition. No side has retained the Champions League title since its change in format in 1992.
Miguel Riopa/AFP/Getty Images
Four-time winner Barcelona will hope the mercurial Lionel Messi will be able to inspire another success in Europe's top club competition.
Messi's moment? —
Four-time winner Barcelona will hope the mercurial Lionel Messi will be able to inspire another success in Europe's top club competition.
LLUIS GENE/AFP/Getty Images
Arjen Robben will be the one to watch when Bayern Munich gets its campaign underway. Bayern, which won the competition in 2013, reached the semifinals last season.
Rocking Robben —
Arjen Robben will be the one to watch when Bayern Munich gets its campaign underway. Bayern, which won the competition in 2013, reached the semifinals last season.
Bongarts
Eden Hazard will hope to spearhead Chelsea's challenge under manager Jose Mourinho. Chelsea won its first Champions League title in 2012.
Hazard lights —
Eden Hazard will hope to spearhead Chelsea's challenge under manager Jose Mourinho. Chelsea won its first Champions League title in 2012.
Mike Hewitt/Getty Images
Benfica will hope it can lift <a href="index.php?page=&url=http%3A%2F%2Fedition.cnn.com%2F2014%2F05%2F14%2Fsport%2Ffootball%2Ffootball-benefica-sevilla%2F">the curse of Bela Guttmann</a> by winning the trophy for the first time since 1962. The Portuguese side have reached the Europa League final in each of the past two seasons but lost on both occasions.
Benfica bounce back? —
Benfica will hope it can lift the curse of Bela Guttmann by winning the trophy for the first time since 1962. The Portuguese side have reached the Europa League final in each of the past two seasons but lost on both occasions.
Photo by Clive Rose/Getty Images
Diego Godin was an integral part of the Atletico Madrid side which reached last year's final. His goal in the final against Real Madrid looked to have earned his side a famous victory only for a late equalizer to force extra time. Real went on to win 4-1 in Lisbon.
Godin for glory —
Diego Godin was an integral part of the Atletico Madrid side which reached last year's final. His goal in the final against Real Madrid looked to have earned his side a famous victory only for a late equalizer to force extra time. Real went on to win 4-1 in Lisbon.
Franck Fife/AFP/Getty
Alexis Sanchez scored his first goal for Arsenal as it came through a tricky playoff tie against Besiktas. This is the 17th consecutive season which Arsenal has participated in the group stage of the Champions League.
Gunning for success —
Alexis Sanchez scored his first goal for Arsenal as it came through a tricky playoff tie against Besiktas. This is the 17th consecutive season which Arsenal has participated in the group stage of the Champions League.
Shaun Botterill/Getty Images
Porto', the 2004 champion will hope Algeria star Yacine Brahimi can inspire his side after a playoff victory over French side Lille.
Porto to pounce —
Porto', the 2004 champion will hope Algeria star Yacine Brahimi can inspire his side after a playoff victory over French side Lille.
Miguel Riopa/AFP/Getty Images
German side Schalke reached the knockout phase of the competition last season only to suffer a merciless thrashing by eventual champion Real Madrid.
Schalke all set —
German side Schalke reached the knockout phase of the competition last season only to suffer a merciless thrashing by eventual champion Real Madrid.
Dennis Grombkowski/Getty Images
Borussia Dortmund, finalist in 2013, will again be one of the teams to watch under coach Jurgen Klopp. Dortmund made it through to the quarterfinals last season where it was narrowly edged out by Real Madrid.
Yellow peril —
Borussia Dortmund, finalist in 2013, will again be one of the teams to watch under coach Jurgen Klopp. Dortmund made it through to the quarterfinals last season where it was narrowly edged out by Real Madrid.
Odd Andersen/AFP/Getty Images
Juventus, led by Andrea Pirlo, will hope to improve on last year's performance in the Champions League where it failed to get past the group stage.
Hopes pinned on Pirlo —
Juventus, led by Andrea Pirlo, will hope to improve on last year's performance in the Champions League where it failed to get past the group stage.
Gabriele Maltinti/Getty Images
Paris Saint-Germain made its way to the quarterfinals last season before suffering defeat against Chelsea. Led by the supremely talented forward Zlatan Ibrahimovic, the French side will be one to watch this year.
Paris to prosper? —
Paris Saint-Germain made its way to the quarterfinals last season before suffering defeat against Chelsea. Led by the supremely talented forward Zlatan Ibrahimovic, the French side will be one to watch this year.
FRANCK FIFE/AFP/Getty Images
Shakhtar Donetsk is struggling to keep hold of its star players due to the ongoing conflict in Ukraine. It will hope that the situation won't detract from its chances of success in the competition.
Shakhtar stress —
Shakhtar Donetsk is struggling to keep hold of its star players due to the ongoing conflict in Ukraine. It will hope that the situation won't detract from its chances of success in the competition.
SERGEI SUPINSKY/AFP/Getty Images/file
FC Basel failed to progress from its group last season despite defeating Chelsea both home and away. The Swiss side will hope to go one better this time around.
Swiss stars —
FC Basel failed to progress from its group last season despite defeating Chelsea both home and away. The Swiss side will hope to go one better this time around.
Michael Kienzler/AFP/Getty Images
Zenit Saint Petersburg came through a tough playoff tie to book its place int the group stage. The Russian side reached the round of 16 in the previous campaign.
Incredible Hulk —
Zenit Saint Petersburg came through a tough playoff tie to book its place int the group stage. The Russian side reached the round of 16 in the previous campaign.
Getty Images
English champion Manchester City made it out of the group stage for the first time in the club's history last season. It will be a force to be reckoned with after losing out to Barcelona last year.
Silva lining —
English champion Manchester City made it out of the group stage for the first time in the club's history last season. It will be a force to be reckoned with after losing out to Barcelona last year.
AFP/Getty Images
Leverkusen, beaten 2-1 in the 2002 final by Real Madrid and Zinedine Zidane's wonderful strike, will be hoping to improve on last year's showing. The German side was thrashed 6-1 on aggregate by PSG in the round of 16.
Leverkusen lurking —
Leverkusen, beaten 2-1 in the 2002 final by Real Madrid and Zinedine Zidane's wonderful strike, will be hoping to improve on last year's showing. The German side was thrashed 6-1 on aggregate by PSG in the round of 16.
Patrik Stollarz/AFP/Getty Images
Olympiacos was left kicking itself last season after taking a 2-0 advantage in the first leg of its second round tie against Manchester United. The Greek side was in pole position to qualify for the quarterfinal but was beaten 3-0 in the second leg at Old Trafford.
Greek tragedy? —
Olympiacos was left kicking itself last season after taking a 2-0 advantage in the first leg of its second round tie against Manchester United. The Greek side was in pole position to qualify for the quarterfinal but was beaten 3-0 in the second leg at Old Trafford.
Yannis Kolesidis/AFP/Getty Images
CSKA Moscow managed just one win from its six group games last season.
CSKA struggles —
CSKA Moscow managed just one win from its six group games last season.
Getty mages/file
Dutch champion Ajax has failed to progress from the group stage in any of its past four attempts. The club, which has won the competition on four occasions, last triumphed in 1995.
Ajax awaits —
Dutch champion Ajax has failed to progress from the group stage in any of its past four attempts. The club, which has won the competition on four occasions, last triumphed in 1995.
Dean Mouhtaropoulos/Getty Images
Steven Gerrard inspired Liverpool to European glory in 2005 with a miraculous win over AC Milan in Istanbul. The five-time winner returns to the tournament for the first time since the 2009-10 edition.
Gerrard's back —
Steven Gerrard inspired Liverpool to European glory in 2005 with a miraculous win over AC Milan in Istanbul. The five-time winner returns to the tournament for the first time since the 2009-10 edition.
Paul Ellis/AFP/Getty Images
William Carvalho is one of Sporting Lisbon's most highly-rated players. The Portuguese side last reached the group stage during the 2008-2009 season.
Sporting chance —
William Carvalho is one of Sporting Lisbon's most highly-rated players. The Portuguese side last reached the group stage during the 2008-2009 season.
Miguel Riopa/AFP/Getty Images
Galatasaray enjoyed a run to the knockout round last season where it was narrowly beaten by Chelsea. The Turkish side has lost striker Didier Drogba who has returned to Chelsea.
Turkish delight —
Galatasaray enjoyed a run to the knockout round last season where it was narrowly beaten by Chelsea. The Turkish side has lost striker Didier Drogba who has returned to Chelsea.
Clive Rose/Getty Images
The new San Mames stadium will host Champions League football after Athletic Bilbao overcame Napoli in the playoff. The club has not featured in the group stage since the 1998-99 season.
Bilbao brilliance —
The new San Mames stadium will host Champions League football after Athletic Bilbao overcame Napoli in the playoff. The club has not featured in the group stage since the 1998-99 season.
Rafa Rivas/AFP/Getty Images
Belgian side Anderlecht will hope to improve on last season's showing where it drew one and lost five of its six group games.
Purple reign —
Belgian side Anderlecht will hope to improve on last season's showing where it drew one and lost five of its six group games.
Laurie Dieffembacq/AFP/Getty Images
Roma is back in the Champions League after a four-year absence. Led by captain Francesco Totti, it is one of the most dangerous teams in pot four.
Roman rule —
Roma is back in the Champions League after a four-year absence. Led by captain Francesco Totti, it is one of the most dangerous teams in pot four.
OLIVIER MORIN/AFP/Getty Images/file
APOEL Nicosia reached the quarterfinals of the Champions League in 2012 but had to come through qualifying and a playoff to secure its place in this year's competition.
APOEL attack —
APOEL Nicosia reached the quarterfinals of the Champions League in 2012 but had to come through qualifying and a playoff to secure its place in this year's competition.
TALAR KALAJIAN/AFP/GettyImages/file
BATE Borisov's 3-1 win over Bayern Munich in 2012 remains the Belorussian club's finest moment in the competition. Last season it was knocked out during the second qualifying round by Shakhtar Donetsk.
BATE set for battle —
BATE Borisov's 3-1 win over Bayern Munich in 2012 remains the Belorussian club's finest moment in the competition. Last season it was knocked out during the second qualifying round by Shakhtar Donetsk.
Getty Images
The Bulgarian side Ludogorets is making its debut in the group stage of the competition. The minnow overcame Steaua Bucharest on penalties to win its playoff tie.
Ludogorets looking forward —
The Bulgarian side Ludogorets is making its debut in the group stage of the competition. The minnow overcame Steaua Bucharest on penalties to win its playoff tie.
Eurofootball/Getty Images
Slovenian side Maribor booked its place in the Champions League group stage following a dramatic victory over 1967 winner Celtic. Tavares scored the crucial away goal as Maribor triumphed 2-1 on aggregate.
Maribor menace —
Slovenian side Maribor booked its place in the Champions League group stage following a dramatic victory over 1967 winner Celtic. Tavares scored the crucial away goal as Maribor triumphed 2-1 on aggregate.
Ian MacNicol/Getty Images
Radamel Falcao will be the man to watch for Monaco after recovering from a knee injury which forced him to miss the World Cup. Monaco reached the Champions League final in 2004 where it was beaten by Porto.
Monaco's main man —
Radamel Falcao will be the man to watch for Monaco after recovering from a knee injury which forced him to miss the World Cup. Monaco reached the Champions League final in 2004 where it was beaten by Porto.
Michael Regan/Getty Images
Malmo, which reached the European Cup final in 1979, is playing in the Champions League group stage for the very first time.
Malmo's moment —
Malmo, which reached the European Cup final in 1979, is playing in the Champions League group stage for the very first time.
Giuseppe Bellini/Getty Images