Arsenal manager Arsene Wenger believes the Gunners will not find it easy against Porto (2/1 to qualify for the next round) in the Champions League on Wednesday.

The north London outfit travel to the Estadio do Dragao having not won on either of their previous visits and with the home side having not lost their in the league all season.

While Chelsea (4/1 to be outright winners of the Champions League) and Manchester United (15/2) both won at Porto (50/1) last year Arsenal (8/1) know they will be up against when they face the 2004 European Champions.

Their task hasn’t been made any easier by an injury to Andrey Arshavin who picked up a hamstring problem during the game against Liverpool (7/1 to win the Europa League) on Wednesday and will now miss the trip to Portugal.

Alex Song and Eduardo are also doubtful for the game and with Robin van Persie already sidelined the Gunners options will be stretched thin again.

While Wenger acknowledges that his side may been seen as favourites he insists he won’t be taking anything for granted.

“From the outside, sometimes you are seen as favourites, but that does not matter,” the Frenchman said.

“Porto have been consistently in the Champions League and you know you will get a tough game, so I will not be surprised.”

While Wenger will want his side to take something from Wednesday’s game he will be well aware that Porto’s (6/4 to win in the match betting) form away from home is less than impressive with Arsenal (6/4) having beaten them 4-0 the last time they met at the Emirates Stadium.