European champions Chelsea will face former winners Juventus, Shakhtar Donetsk of Ukraine and Danish newcomers FC Nordsjaelland at the start of their title defence following The Champions League group stage draw today.
An intriguing series of games is in prospect in Group D with nine-times European champions Real Madrid grouped with English champions Manchester City, Dutch league winners Ajax Amsterdam and German champions Borussia Dortmund.
Bayern Munich, who lost to Chelsea in last season's Champions League final, will face Valencia, Lille and BATE Borisov of Belarus in Group F.
Chelsea were placed in a tough group with Juventus, Shakhtar Donetsk and Nordsjaelland.
"It is not going to be easy. Manchester United thought they had an easy passage last season and went out early. You cannot afford to make that mistake," Chelsea club secretary Dave Barnard told reporters.
Real director Emilio Butragueno told Spanish television His team had not had much luck after being drawn with Manchester City, Ajax and Dortmund.
"It's a very tough group, every game will be very tight with a lot of tension," he said. "We need to prepare very well. City are a very strong team after an enormous investment in recent years and they will be a rival of the highest level."
Bayern Munich, runners-up to Dortmund in the Bundesliga last season, face Valencia, who they beat on penalties in the 2001 Champions League final, Lille and BATE.
"I see Valencia as our strongest opponents in this group, but in any case it's our duty to reach the quarter-finals, preferably by winning the group," Bayern captain Philipp Lahm told reporters.
Barcelona, the strong favourites last year until they lost to Chelsea in the semi-finals, face their old rivals Benfica, Spartak Moscow and Celtic.
The rivalry between Barcelona and Benfica goes back to the early days of European club soccer and the 1961 final when Benfica beat Barcelona 3-2 in Berne to win the first of their two European Cups, a game still remembered as a classic.
Barca skipper Andres Iniesta, in Monaco and named as UEFA's Best Player in Europe last season, told guests in the auditorium: "The Champions League is an incredibly difficult competition to win, and we will respect every side that we have to face in it."
Lionel Messi, who scored 73 goals for Barca last season and was also in Monaco, added: "Sometimes luck helps decides the Champions League as Chelsea discovered last season. It's a tough draw but hopefully we can do better this season than last."
Manchester United, the three-times European champions who failed to get past the group stage last season but are back for a record 18th appearance in the competition, will face Braga, Galatasaray and CFR Cluj and should progress comfortably
The draw included 11 former European champions as well as holders Chelsea, 20 teams who competed last season and three newcomers including Montpellier, who won the French League for the first time.
They were drawn in the same group as Arsenal, Schalke 04 and Olympiakos.
"Arsenal are a European great, Olympiakos's fans are among the hottest and Schalke represent the German seriousness," Montpellier coach Rene Girard said. "Obviously, we will fight as hard as we can, we did not do all this for nothing."
Paris St Germain, who finished as runners-up to Montpellier and are back in the competition for the first time since 2004-05, will play Porto, Dynamo Kiev and Dinamo Zagreb.
"The group is quite open, it could have been much more complicated," PSG captain Christophe Jallet said. "We escaped from the big fishes. We have our chances to move through, so we hope we'll qualify. We should beware of Porto, they are the favourites. But there is an opportunity to take."
The competition starts on September 18-19 with the group stage ending in the first week of December.
The final is being staged at Wembley for the second time in three seasons on May 25 as part of the celebrations marking the 150th anniversary of the founding of the English FA, the world's oldest, in 1863.