Wenger calls for clarity on referee ranking
Wenger was incensed by Swedish referee Martin Hansson's decision to allow Porto a quickly-taken indirect free kick that led to their second goal in their 2-1 Champions League round-of-16, first-leg victory on Wednesday.
Wenger said on Friday that UEFA should review their refereeing structure.
"First of all, it has to be clarified how they nominate referees for games. They (UEFA) have to be much more open on how they rate their referees. Nobody really knows how they name their referees," he told a news conference ahead of Arsenal's Premier League game with Sunderland on Saturday.
"Where is the ranking of the referees? I believe too much has gone on in the last 30 years. What has happened is not good for football."
Asked if Hansson, the referee who missed Thierry Henry's handball in France's World Cup qualifier against Ireland last November, should be refereeing at Champions League level, Wenger said: "I don't know.
"Usually I trust the referee. But he missed a 100 percent penalty on (Tomas) Rosicky. That is a judgement in a second that I can accept.
"For me, the back-pass of Sol Campbell was accidental. He has judged it is voluntary. OK, we have a difference there, that I can accept. But technically he made at least five mistakes."
Referring to the goal which came after goalkeeper Lukasz Fabianski picked up Campbell's back-pass, Wenger said: "The referee made so many mistakes.
"His body position was wrong, where he stands is completely wrong at the moment he gave the free-kick.
"He takes the ball from Lucasz Fabianski. They score. What he does doesn't make common sense and is against the rules of the referees.
"So when a guy makes so many technical mistakes that is not even linked to judgement, I believe he is not competent."
Arsenal, hit by a succession of injuries in recent weeks, hope to have first choice Manuel Almunia back in goal on Saturday if his injured finger has healed.