The Gunners are without five of their first-team regulars, including goalkeeper Manuel Almunia and Russian playmaker Andrei Arshavin.
With centre-half William Gallas, defensive midfielder Alex Song and Croatia striker Eduardo also not among the 18-man travelling party, the Gunners are somewhat light as they prepare for the first leg of their last-16 clash.
Wenger, though, insists being low on numbers should not be an issue for the Gunners, who did not have a game at the weekend.
“It is difficult to say how long they will be out,” said the Arsenal manager. “But it is not a serious concern.
“The concern is that the players who are here perform at their best.
“It is part of the season you do not always have all the players available to select but I am not bothered by that.”
With Gallas unavailable because of a calf problem, Sol Campbell could be in line for his first European appearance with the Gunners since scoring in the 2006 Champions League final against Barcelona.
The 35-year-old has been used only twice since securing a shock return to the club he helped to so much success between 2001 and 2006.
And Wenger believes Campbell still has plenty left to offer.
“Sol’s experience can be important tomorrow,” said the Arsenal manager.
“For a central defender, it is a bit special (to still be playing at 35) but, as long as you are hungry to work hard to keep yourself fit and you are not bothered by injuries, then a central defender can play three or four years longer than a striker.”
Arsenal have seen their domestic title hopes boosted after the top two both dropped points in the last set of Premier League matches.
Wenger, though, knows the Gunners will face a stern test of their European credentials tonight against the Portuguese champions, who were beaten 1-0 here by Chelsea in the group stages and by Cristiano Ronaldo’s wonder strike for Manchester United in last season’s quarter-final.
“It is always difficult in Porto. They always have a committed team which is technically very good,” said Wenger, whose side have yet to win in Porto, following a 2-0 defeat when already safely qualified in December 2008 and a goalless draw four seasons ago.
“You respect a team like Porto because you know they will always give you a good game.”
The Arsenal manager added: “It is the last 16, a cup draw, so it is tight.
“We have 180 minutes to be on top and no-one can predict what will happen. We will try to do our best.”
With Arshavin and Eduardo both unavailable, Wenger could turn to Nicklas Bendtner to lead the attack.
The 22-year-old Denmark striker has just returned to fitness following a three-month lay-off after groin surgery, which was part of the reason the Arsenal manager did not venture into the January transfer market for another forward.
Wenger said: “I think we will see the best of him now as he is getting to the best age for a striker.
“Of course, he will still improve and learn a lot but, at 22, you have to start to play at the top level. Nicklas is a boy who has a big potential.
“He arrived at the age of 15 and we work very hard with these players to get them to a level where they are today.
“Of course, we do not believe in a player for four or five years and then suddenly stop because people say you should buy a striker.
“We have a line of conduct and we keep believing in what we have done up until now and we hope they pay us back.”
Porto coach Jesualdo Ferreira believes tonight’s clash with Arsenal will be a good test of how far his team have progressed.
Ferreira’s men head into tonight’s tie in confident mood, having lost only one of their previous nine matches domestically.
And Ferreira has urged his players to prove their worth tonight.
“Porto are going through a good period and I think this is the ideal opponent for us to evaluate where we are, in terms of growth and ability,” he said. “This game for us has the importance of being a test of quality.
“We really want to get through to the quarter-finals, even though we know that this opponent was one of the most difficult that we could have been drawn against.
“In the last four years we’ve reached the last 16, last year we were in the quarter-finals, and this year we want to continue again in the competition.”
Ferreira added: “This is the first part of a qualifier, which both teams want to win. Not to concede at home is fundamental, but winning is most important. It is only victories that give us more confidence and prestige.”
Ferreira will be boosted by the return of Hulk to the squad.
The imposing centre-forward has been provisionally suspended for six months by the Portuguese football federation for his part in a tunnel bust-up involving Benfica stewards last December but is free to play in European ties.
Midfielder Raul Meireles, who has been sidelined for a month, also returns as does Alvaro Pereira.