Walker, who has earned five senior caps having been part of the Under 19 squad at Euro 2009, believes the experience he had provided a sound footing from which he could make an impact at the highest level.
He said: "It's vital experience for younger players. I went to Ukraine for the Euro finals, and just to play tournament football and be away from home for a longer period of time was a massive learning curve for me.
"It makes you grow up a lot quicker too. I didn't play for the Under 16s or Under 17s, as I was a centre-forward in those days, which was very different to being a full-back.
"But I got my chance when I was playing full-back for the 19s, then the 21s and now the seniors."