Walker has admitted he would rather not be playing at centre back for England, but insists he is happy to sacrifice himself for the sake of Southgate's plans.
"Is centre back my preferred position? Of course not. I want to play right back," said Walker.
"I have worked my whole life to get to where I am now in a World Cup squad, and to showcase my talent in the World Cup stage, playing in my position.
"But I'm a team player. I will do anything for the team. If that means the gaffer thinks to help the team out I should play there I am all for it.
"I have been playing professionally since I was 18 at right back. To get to your first World Cup and probably not be playing in your preferred position where you want to showcase your talent is not disappointing but it is like, 'OK it is a little bit of a step back'.
"I have to move on from it. I'm a defender first and foremost, and if I'm playing right centre half I am even more of a defender than the wing backs. If I can get forward I am sure you will see me up there. I have to be professional. I have to manage the game correctly, and see what we are doing in the game."