Southgate resigned from his role as the Football Association`s technical director earlier this year after deciding he could not commit himself in the long term.
But in an interview with the Independent on Thursday morning, the 57-cap defender has admitted that he is concerned for the future of the England team.
He said: "Really, are we serious about international football? Or is our football geared towards the clubs?
"Because in the end it's always difficult to get the release of players for international junior tournaments, and sometimes that`s because clubs want their players to play in friendlies or go on friendly tours.
"So at some point we`ve got to decide are we really serious about our national team or is it just an add-on?"
Southgate added that while he was unhappy with the fact that the FA do not control the movements of junior players, he quit his job for personal reasons rather than out of protest.
"Clearly I`m not comfortable with the fact that the FA don`t control youth development," he said.
"And as technical director you would be accountable for something that perhaps you don`t control. But other than that it was a personal, career decision.
"I just felt at this moment in time, this wasn`t what I wanted to do. It would have meant committing myself to that role for at least three years. You have to decide what works for you and your family."