Although defeat in Porto failed to jeopardise qualification from Group G, Arsene Wenger's decision to leave a host of first-choice players in England could have severely hampered Arsenal's hopes of Champions League glory.

It was always difficult to believe the Frenchman's insistence that finishing above the Portuguese champions was a high priority while at the same time the Gunners boss disarmed his most potent artillery that would have helped achieve the mission.

And how they missed Emmanuel Adebayor and Robin van Persie, the strikers who scored two apiece during a 4-0 stroll against the same opponents in September, and captain Cesc Fabregas, who has a 100 per cent record in the role, among others.

The merits of topping the group are questionable as the competition's business end gets under way after the first knockout round draw next Friday.

By finishing second, Arsenal have avoided Real Madrid and Inter Milan but it is difficult to escape the feeling that their indifferent attitude towards a match they only needed to draw could ultimately come back to haunt them. Juventus, Barcelona, Roma, Bayern Munich and Panathinaikos lie in wait as possible opponents, presumably with the Gunners praying for a meeting with the latter, thereby avoiding four of the traditional powerhouses of European football.

Furthermore, in 16 years of Champions League football in its current format, only four sides have lifted the trophy in May having not won their original group. But Wenger was unmoved to lose here in Portugal - his 700th game in charge at Arsenal.

"We can fight with everybody in Europe and can qualify against anybody," said the 59-year-old.

"It is important now to come back in the Premier League and be in a good position. We now have some time to focus on that. We will see who we get in the draw and then look at the Champions League again in February."

And it must be remembered Wenger is right in the sense that Arsenal are capable of beating any side anywhere in the world. Sterling away performances against Real Madrid and Juventus in 2006 and AC Milan last season are testament to that, but there are certain traits in the 2008 incarnation that are cause for considerable alarm.

Remember the early season vulnerability from set-pieces that prompted question marks over the height of Arsenal's back four? It's back - conceding the simplest of goals from a corner broke the relative serenity the Gunners enjoyed in the opening 39 minutes at the Estadio do Dragao.

Although it was not a lack of inches that cost Wenger's side, more the disinterest shown by Abou Diaby in not bothering to challenge for the ball from Jorge Rolando's corner - a moment that encapsulated the lackadaisical approach of the visitors.

When the second came courtesy of a fine through ball from Fernando and a superb Lisandro Lopez finish, there was simply no way back for the lacklustre Gunners.

Wenger said: "When we are 2-0 down the belief was not there and we were not strong enough to come back."

The sub-plot to this match was the return of Emmanuel Eboue after he was booed against Wigan on Saturday. Arsenal's travelling supporters were intent on showing their support for the maligned Ivory Coast international, singing Eboue's name both as the players warmed up before kick-off and at the beginning of the match.

Playing in his more familiar and original right-back role, his night consisted of losing out time and again to winger Cristian Rodriguez, a yellow card for a crude challenge on the same player, the usual histrionics and playing Lisandro onside for the decisive second goal. Wenger said: "He got the support of the fans and he did all right, but it will take time."

Victory at Middlesbrough on Saturday is imperative now if the Frenchman can at least partially vindicate leaving so many first-choice players behind.

He said: "We had some injured players at home and this was the only match where we could try and protect them for our next fixture in the Premier League. Many of the players who stayed at home were a doubt any way."

Wenger signalled for his players to salute the fans at the end but if anyone short changed them last night, it was the Gunners boss as much as anyone else.