Wenger said: "I could only advise you to take advantage of it and call him up for the England squad. Almunia came here without a CV so he had to make a name with his performances.
"It was not easy because he had to get experience at a big club. I knew he was good but how could he be Arsenal's keeper? Only by playing.
"He had never played for a big club before and made some mistakes, but he has gained confidence and calmness. He is a good keeper.
"Everyone makes mistakes. Van der Sar makes mistakes.
"But it was more difficult for Almunia because he was already under pressure from an outstanding goalkeeper behind him.
"That was a tough test. If you play bad games, you are under pressure immediately."