Matchday 1 number crunching

Ahead of the start of the group stage we take a glance over some of the eye-catching facts and figures involving the 32 UEFA Champions League contenders as Iker Casillas prepares for a significant milestone.

0 Number of goals Greek champions Olympiacos CFP have conceded after six competitive matches this season, including four UEFA Champions League qualifying victories over ŠK Slovan Bratislava and FC Sheriff.

1 Matches Juande Ramos has been in charge of PFC CSKA Moskva since replacing Zico as coach on 10 September. He kicked off with a 3-0 win at home to PFC Krylya Sovetov Samara on Saturday.

5 Players FC Porto flew home in the club's private jet after Colombia's FIFA World Cup qualifier against Uruguay last week. Fucile, Álvaro Pereira, Cristián Rodríguez, Fredy Guarín and Falcao all made the trip.

7 Penalties Alejandro Domínguez has scored for FC Rubin Kazan in his last seven league games. The only team he failed to score from the spot against in that run was FC Terek Grozny, though he did register from open play.

8 Group-stage debutants in the UEFA Champions League this season: APOEL FC, AZ Alkmaar, Debreceni VSC, FC Rubin Kazan, FC Unirea Urziceni, FC Zürich, R. Standard de Liège and VfL Wolfsburg.

8 Goals Beşiktaş JK conceded the last time they faced a Premier League team – Liverpool FC – in the 2006/07 group stage. It was their biggest defeat in Europe as well as in the 17-year history of the UEFA Champions League. They host Manchester United FC in Group B on Tuesday.

15 Seasons Manchester United and Porto have each participated in the group stage including this term, a competition record.

16 Years since Olympique de Marseille beat AC Milan in final of the 1993 UEFA Champions League to become the first French side to win the European Champion Clubs' Cup. The two sides meet again at the Stade Vélodrome on Tuesday.

17 Length of FC Girondins de Bordeaux's unbeaten run in all competitions. They have won 16, their one draw coming at Marseille on 30 August.

18 Chelsea are on an 18-match unbeaten run in the UEFA Champions League at Stamford Bridge dating back to February 2006 when FC Barcelona triumphed 2-1 in the first knockout round first leg.

25 Last season's final defeat by Barcelona ended United's 25-match unbeaten run – the longest in the competition's history. They had last lost at Milan on 2 May 2007, winning 15 of their subsequent 25 games, drawing ten.

99 Iker Casillas will make his 100th appearance in UEFA club competition should he feature against FC Zürich.

To read more about the stats behind this week's matches, click here to access uefa.com's UEFA Champions League press kits then press the PK button next to the match of your choice.