The Costa Rica international agreed terms with the Gunners last week.
"Joel is a young prospect, he has talent and he can play right, left or centrally," Wenger told the Official Arsenal Matchday Programme. "We took a gamble on him but, from what we have seen, it is worth taking.
"Campbell could join the Club, Gervinho has joined the Club, Carl Jenkinson and Alex Oxlade-Chamberlain have joined the Club and people forget that. You can see that Gervinho has had a big impact as well.
"Sometimes you feel the reputation of the player is punished by the fact he did not have a massive transfer fee. You would like people to look just at the quality of the players and feel if they are Arsenal players or not."