Almunia has become Arsenal boss Arsene Wenger's first-choice goalkeeper since the third game of the season, much to the annoyance of Lehmann. However, Almunia insists he has the required experience.
"I am enjoying my best form since I arrived at Arsenal," Almunia said in the Daily Mirror.
"It's not easy to be in the title race but it is in the Premier League and the UEFA Champions League that I have had my best moments.
"I always had confidence in my coach that he would give me my chance and now I am proving that I deserve to be in the position.
"The coach decides who is the keeper. I always accept the choice and never made comments when I was on the bench.
"Now I am the No.1 and I want that situation to stay the same for the rest of the season."