Here we assess each club.

ARSENAL

Pedigree: This season marks Arsenal's ninth Champions League campaign (since the format changed from the European Cup), their greatest coming in 2005/06 when they reached the final only to lose 2-1 to Barcelona. The Gunners have twice reached the quarter-finals and the UEFA Cup final in 2000.

Manager: Arsene Wenger. Highly successful domestically but the Frenchman has been unable to replicate this in Europe.

Star player: Emmanuel Adebayor. The striker is on top form and has scored in nine successive games as the Gunners top the Barclays Premier League.

Odds: 10-1 (William Hill)

BARCELONA

Pedigree: This will be Barca's ninth campaign during which they have lifted the trophy once when they beat Arsenal in 2006. Barca have also reached the semi-finals twice and quarter-final once.

Manager: Frank Rijkaard. At the end of his third season at the Nou Camp, the Dutchman became only the fifth man to have lifted the European Cup as both a player and manager.

Key player: Lionel Messi. The young Argentina forward has scored four goals in the Champions League this season.

Odds: 3-1

CELTIC

Pedigree: The first British winners of the Champions League in its previous inception as the European Cup in 1967. This is Celtic's fourth successive Champions League campaign and they reached the knockout stage last year where they were beaten 1-0 on aggregate by eventual winners AC Milan.

Manager: Gordon Strachan. The former Scotland midfielder helped Aberdeen win the UEFA Cup under Sir Alex Ferguson. Won the SPL last year but are four points adrift of Rangers this year.

Key player: Shunsuke Nakamura. The Japanese right-sided midfielder can both create and execute goalscoring opportunities and is also adept at set-pieces.

Odds: 150-1

CHELSEA

Pedigree: Their sixth time in the Champions League, Chelsea have reached the semi-finals in three of the last four years.

Manager: Avram Grant. Took over from Jose Mourinho and is attempting to guide the Blues to the quadruple having already reached the Carling Cup final.

Key player: Didier Drogba. The Ivory Coast forward displays fearsome power and pace and is equally adept in the air or on the ground.

Odds: 13-2

FENERBAHCE

Pedigree: This is only their third appearance in the Champions League making this the furthest they have progressed after playing in the group stages in 2005-06.

Manager: Zico. The former World Cup winner is in his second season with the Turkish club and has led them to the Turkish Cup and Super Lig title as well as guiding them in Europe.

Key player: Roberto Carlos. Another Brazilian former World Cup winner, Carlos' experience is a key reason in the club's success.

Odds: 100-1

INTER MILAN

Pedigree: Won the European Cup four times in the 1960s and early 70s. This is Inter's sixth Champions League campaign, their best effort coming in 2002-03 where they reached the semi-finals.

Manager: Roberto Mancini. The former Italy striker has led Inter to the last two Scudetti as well as a commanding lead in this year's Serie A. Has made little impact on Europe as yet.

Key player: Zlatan Ibrahimovic. The Sweden striker has scored five times in Europe this season.

Odds: 10-1

LIVERPOOL

Pedigree: Unquestioned, the Reds are the most successful English club in European history. Have won the European Cup/Champions League five times and appeared in the final twice in the last three years.

Manager: Rafael Benitez. Led Sevilla to the UEFA Cup before inspiring Liverpool to come back from 3-0 down to 3-3 in the Champions League final in 2005 against AC Milan and eventual victory on penalties. Lost last year's final against the same opponents.

Key player: Fernando Torres. The striker has impressed since his £26.5million move from Atletico Madrid. Has pace and vision and is calm in front of goal.

Odds: 16-1

LYON

Pedigree: Sixth Champions League campaign, Lyon contested three consecutive quarter-finals from the 2003-04 season.

Manager: Alain Perrin. The former Portsmouth manager guided the French team to the knockout stages after an emphatic win at Rangers in their final group stage game.

Key player: Karim Benzema. Can play either on the wing or as a striker. Has great vision and is clinical in front of goal.

Odds: 25-1

MANCHESTER UNITED

Pedigree: Twice the champions of Europe, the last time in 1998-99 when they scored twice in added time to beat Bayern Munich 2-1.

Manager: Sir Alex Ferguson. Celebrated 21 years with the club in 2007. Has won nine league titles and five FA Cups as well as the European Cup Winners' Cup in 1991.

Key player: Cristiano Ronaldo. Hugely important for United, the Portuguese winger has pace and vision and is currently joint top scorer in the Premier League.

Odds: 5-1

AC MILAN

Pedigree: Defending champions, Milan have won the Champions League three times as well as the European Cup on four occasions.

Manager: Carlo Ancelotti. One of five to have lifted Europe's top club honour as a player and manager. Has won the competition twice and guided them back from the heartbreak of the defeat by Liverpool to gain revenge over the same club last May.

Key player: Kaka. Will help the team overcome the loss of Ronaldo with a serious knee injury. The striker was named world footballer of the year in 2007.

Odds: 12-1

OLYMPIACOS

Pedigree: Tenth Champions League campaign, their best effort came in 1998-99 when they reached the quarter-final.

Manager: Panagiotis Lemonis. Helped the club to their 10th league title in 11 years last year and finished level on points with Real Madrid in the group stage.

Key player: Darko Kovacevic. The Serbia forward has been instrumental for the Greek side scoring three goals in this campaign.

Odds: 125-1

PORTO

Pedigree: The Portuguese club have twice been European champions, most recently in the 2003-04 season when they beat Monaco under Jose Mourinho after first winning in 1987. Won the UEFA Cup in 2003.

Manager: Jesualdo Ferreira. Won the league title and qualified for the Champions League in his first season.

Key player: Ricardo Quaresma. Plays as a left winger and has superb technique as well as dribbling skills. Often compared to Cristiano Ronaldo.

Odds: 33-1

REAL MADRID

Pedigree: The most successful club in UEFA club competition history, Real won the first five European Cups, won on one other occasion and have also been losing finalists three times. Won the Champions League three times, most recently in 2001.

Manager: Bernd Schuster. Joined Real from Getafe last summer the former West Germany midfielder has an impeccable international pedigree.

Key player: Ruud van Nistelrooy. Well known from his Manchester United days, the Dutchman has a formidable scoring record and has four goals in this season's Champions League.

Odds: 9-1

ROMA

Pedigree: Fifth season in the Champions League, their best effort came last year when they reached the quarter-finals. However, it is remembered for their 7-1 defeat by a rampant Manchester United.

Manager: Luciano Spalletti. The first coach to guide former club Udinese to the Champions League in 2004 but left to replace Fabio Capello at Roma. Set a record of 11 consecutive Serie A wins and was second in the league last year.

Key player: Francesco Totti. The 31-year-old has immense experience having spent his entire career at the Stadio Olimpico. Can be a striker or attacking midfielder.

Odds: 28-1.

SCHALKE 04

Pedigree: Have only appeared in the Champions League on one previous occasion. Won the UEFA Cup in 2006-07.

Manager: Mirko Slomka. Never played professionally he began as a youth team coach at Hannover 96 developing players like Gerald Asamoah.

Key player: Gerald Asamoah. Born in Ghana, he has great pace and strength. Scored one goal in this year's Champions League.

Odds: 66-1

SEVILLA

Pedigree: First appearance in the Champions League, Sevilla have won the last two UEFA Cups.

Manager: Manuel Jimenez. Replaced Juande Ramos who went to Tottenham. Former Spain defender and Rojiblancos youth team coach.

Key player: Luis Fabiano. The Brazil striker has been outstanding this season with his strength, pace and cool in front of goal and has scored four goals in the Champions League this season.

Odds: 14-1