Sir Alex Ferguson admitted Manchester United's re-match with Roma will provide the talking point of their Champions League campaign.
Last season's quarter-final tussle between the pair was scarred by violence, with fighting marring both legs.
United supporters were attacked by fans and police in the Stadio Olimpico, with the hosts fined £31,000 for the behaviour of their supporters, while United were ordered to pay out £14,500 by UEFA.
The trouble overshadowed one of the finest European performances of all-time by Sir Alex Ferguson's men, who thrashed the Serie A outfit 7-1 at Old Trafford after losing the first leg 2-1.
'That will be the talking point after last season,' said Ferguson.
However, the United boss also has other major challenges to ponder, not least a testing trip to Dynamo Kiev and two encounters with Sporting Lisbon, the club which provided the Red Devils with both Cistiano Ronaldo and Nani.
'It is a very tight group,' he added. 'Dynamo Kiev are a good side.
'We also have two of Sporting Lisbon's former players, so we know a bit about them.'
United's only previous meeting with Sporting came during a European Cup Winners' Cup campaign 44 years ago, when a team containing George Best, Bobby Charlton and Denis Law were hammered 5-0 in the Portuguese capital.
Ferguson will hope to avoid a repeat and has already set his side the task of gaining 10 points to get them on the road to bettering last season's semi-final berth.
'The whole group possesses some very interesting aspects,' he said.
'We hope we can get 10 points. It will be difficult but if we can get that I think we will qualify.'
Arsenal managing director Keith Edelman believes six 'tough' games await the Gunners after they were drawn with group stage newcomers Slavia Prague, Steaua Bucharest and either UEFA Cup holders Sevilla or AEK Athens, who play their rescheduled second leg on Monday.
He told Sky Sports News: 'I think it's the first time we have never played one of the teams we have we have been drawn against.
'We have played in Prague quite a bit over the last few years, Bucharest we have never been to and it's going to be a new challenge for us, we have played a lot in Athens and Sevilla, of course, had a great run in the UEFA Cup and have done extremely well in that competition.
'I think they are all tough. The thing about the Champions League is it's an exciting competition but also a very challenging one.
'We have a very good young team full of enthusiasm. There is great team morale and we are confident we can have a great season and in Arsene (Wenger) pulling together enormous talent. We feel very positive about that.'
Chelsea chief executive Peter Kenyon described the Champions League as the Blues' 'elusive competition' and set his sights on securing the trophy this year.
'The big difference for us this year is we're seeded. We've been in two semi-finals in the last four years and got through the group stages every year,' he said.
'It's the elusive competition for us really but there's a determination and that is fuelled by a squad we believe we've strengthened.'
Kenyon added on Sky Sports News: 'It's not frustrating at all (to have missed out on a place in the final) but there's a huge expectation within Chelsea to get to the next stage.
'We've had our share of semis, so obviously the next stage is to get to the final.
'This is clearly a big ambition for us and one we'd like to pull off.'
Manchester United chief executive David Gill insists they will head to Roma with no fears after the sides were drawn together in Group F along with Sporting Lisbon and Dynamo Kiev.
Last season's quarter-final tussle between the pair was scarred by violence, with fighting marring both legs but Gill revealed United were 'not concerned at all' by the pairing.
'What we need to do is do our homework and work very closely with Roma,' Gill told Sky Sports News. 'I'm sure the lessons have been learnt by Roma and the authorities from last year.
'We believe our fans acted very properly and were found to be broadly blameless. I think we need to all to work together to ensure the game is remembered for what happens on the field as opposed to off it.
'We will discuss it with Roma and UEFA to make sure it is remembered for what happens on the field and make sure everyone travels in safety.'
He added: 'We have got to be confident, we are confident against every team we play. We have a great squad and are looking forward to the challenge of the Champions League immensely.'