The 30-year-old has yet to be capped by Spain and will qualify to play for England in a year's time having spent four years with the north London club.
"They (Spain) have never, never called me," said Almunia.
"If other people want me, I have to study my situation and take a decision because it is good for me - I will not close myself to anything."
Almunia has been in impressive form all season having kept 11 clean sheets in 22 games this season, relegating German international Jens Lehmann to the substitutes' bench.
Almunia's admission could give new England manager Fabio Capello a further option to explore as he looks for a long-term solution to the goalkeeping problem.
"I always say I have to wait to see what is happening at that moment, or which goalkeeper England has, or which goalkeeper Spain has, look at the situation and take a decision," said the Pamplona-born keeper.
"It would be a big decision but I wouldn't care if I had two days to take it."
"If you give them a little thing I think they love you, and that's fantastic. That doesn't happen in Spain, no," he said.
"That's because in England the people are more passionate and the people here are more humble.
"If they receive something, even a little thing, they give you double. For a player that's unbelievable."