Walker was playing in the Championship with QPR just over a month ago but is now in contention to win his first England cap in Wednesday's friendly with Denmark in Copenhagen.
He is on loan from Tottenham to Villa for the remainder of the season and scored his first Premier League goal in Saturday's 2-2 draw with Fulham.
Walker said: "It was nice to hear people saying that Fabio Capello was name-checking me recently and that he was looking at me. To get a call-up has always been a dream. It has come quickly. That's the way football goes.
"One minute I am playing for QPR in the Championship, next minute I am at Villa and now this has happened (England). These things can happen. I've played for Under-19s, 20s and 21s so the next step is the full squad."
Walker added: "I've always looked up to Gary Neville. He's not the quickest and isn't really like an Ashley Cole getting forward. But not many people beat him. You're not going to stay at Manchester United for nearly 20 years if you're not good at defending. When I became a right-back my coach told me 'look at Gary Neville and Ashley Cole'. That's what I've done."
Source: PA
Source: PA