LONDON, Sept 25 (Reuters) - European champions Barcelona drew 1-1 with Valencia in an entertaining match at the Nou Camp on Sunday night and both teams will look to go one better on Matchday Two in the Champions League this week.
Barca lost their perfect record in La Liga but, having started with a 5-0 win over Levski Sofia, will look to maintain it in Europe at Werder Bremen on Wednesday by seeking to inflict a second successive Champions League defeat on the Germans.
Valencia, who started their campaign with a 4-2 win at Olympiakos Pireaus, will also aim for a second straight victory when they host AS Roma on the same night.
Arsenal, Champions League runners-up last season and also off to a good start in Group G with a 2-1 win in Hamburg two weeks ago, host 2004 European champions Porto in the first group phase match at their new Emirates Stadium.
The game comes in the week Arsene Wenger celebrates 10 years as manager and Arsenal would love nothing more than to fire off a victory salute in his honour on Tuesday.
AC Milan will return to the Champions League with a sense of relief after a frustrating 0-0 draw with Livorno on Saturday.
The six-times European champions had made a 100 percent start to the season, racking up three wins in Serie A, two in Champions League preliminaries and one in their Group H opener against AEK Athens.
Captain Paolo Maldini will miss the trip to Lille having injured his left thigh against Livorno. Kakha Kaladze is expected to take the veteran defender's place.
Italy striker Alberto Gilardino was rested for Saturday's match and should be fresh to replace Ricardo Oliveira.
Lille collapsed in the second half of their Ligue 1 clash at Olympique Lyon on Saturday as they lost 4-1 and know they will need a spectacular improvement to trouble Milan.
"We realise we will have to play a lot better against Milan," said coach Claude Puel.
Lille, whose stadium does not meet UEFA's standards, have to play their home Champions League matches in nearby Lens.
Lyon, meanwhile, enjoyed warming up for Tuesday's visit to Steaua Bucharest in style against northerners Lille.
"We must not underestimate Bucharest," said Lyon president Jean-Michel Aulas. "They are a strong side and have just won 4-1 in Kiev. We must not take them lightly."
Bordeaux, last season's Ligue 1 runners-up, boosted morale with a 2-1 win over Troyes that lifted them to sixth.
They were missing Johan Micoud because of a groin strain but their Brazilian manager Ricardo was hoping his playmaker would be fit to face PSV Eindhoven on Wednesday.
Two of Germany's three Champions League contenders met at the weekend with Hamburg SV drawing at home to Werder Bremen.
Miroslav Klose, the World Cup top scorer, missed the game because of a bruised foot but has a good chance of recovering in time to face Barcelona on Wednesday.
Hamburg keeper Sascha Kirschstein will be suspended for the trip to CSKA Moscow following his sending-off against Arsenal. Stefan Waechter will step in.
Juan Pablo Sorin made his debut in the 1-1 Bundesliga draw against Werder following injury and stands by for his first Champions League match in Hamburg's colours.
Bayern midfielder Owen Hargreaves, who has a broken leg, was replaced by Andreas Ottl for Saturday's 2-1 win over Alemannia Aachen.
Ottl will vie with Martin Demichelis to partner Mark van Bommel in central midfield on Wednesday when Bayern visit Inter.
Van Bommel's place is secure after he scored his second goal in two league games since moving from Barcelona.
Inter need to tighten up in defence against Bayern. Winning 4-0 with 15 minutes left against Chievo Verona in Serie A on Sunday, they stopped concentrating, let three goals in and ended up with nerves jangling to hang on for a 4-3 win.