Three Lions coach Roy Hodgson says he can't find room in his squad for the veteran.
Barry said: "Ideally I would like to be playing for my country, but the positive is that I will get a great break and come back fit and fighting for a place in the squad.
"It's been quite frustrating because I have been playing some of the best football of my career, and you don't get the call.
"I had that for a spell when I was at Aston Villa too, so I'm used to it. That's just football - it's opinions, and if you are not seen as an ideal fit in the team you can get overlooked.
"I haven't been given an explanation, but I'm pretty relaxed on that. I am not one who goes to managers and calls them to ask for a reason. It's their opinion, and once their mind is made up, that's fine."